You first met Jodie at a trendy coffeeshop, a set that fits perfectly the sitcom your life seems to have become. Sitting in a red velvet chair, you were lorded over by local artists' paintings of human anatomy, usually eyes and aortas featured next to cut-and-pasted text from the Used Bookstore's discount nonfiction section. You were taking notes on the other patrons; since your life had become an objectively observable phenomenon, it only made sense to give its secondary characters the same treatment.
      Your leg was bouncing, and the woman to your right, who became Jodie, said, "You look like you're about to blast off."
      "Sorry," you replied. "It's one of my coping mechanisms."
      You were aware, as you looked at her screen and noted that she was viewing images of the Mandelbrot Set, that if the conversation lost momentum, she would go back to her fractals, which were more interesting and universal than you anyway, so you said, "I used to be shy," as if this were an explanation for your behavior, and you made the words sound like a confession, because confessions make people trust you. "But there were a lot of great things I could have said."
      She replied, "I believe you," and because the conversation had become suddenly serious, you stepped onto the first limb of your life and said, "Do you maybe want to get coffee sometime?"
      She responded, "We already are."
      You blushed, smiled, forced a breath, and watched her lift her cup in a cheers-ing motion. The cup slipped from her hand. You watched your shirt turn a darker, hotter shade, then watched her face do the same. Two hands accidentally touched as you both went for the napkin dispenser. Her mouth said, "I'm sorry—I'm a little clumsy," and you listened to yourself respond, in a voice that sounded very far away, "It's okay—I'm a little       Because her she no longer had coffee, it was the perfect time to ask her out for more. It was funny. You were funny, and she said yes, she would, yes.

At a graduate mathematics lab at the University, the air is always filled with the noise of supercomputers and chit-chat, and although your CPU adds to the former and your voice to the latter, your mind feels separate from the scene, as if you are floating above it with a camera, watching and recording the others, of which your body seems to be one.
      You are able to trace back that feeling of distance, of dichotomy between brain and body, to last Friday when you went out with your classmates after a colloquium entitled "Equations Model Everything." You had seen the talk advertised in the Math Department's weekly newsletter, a publication the faculty thought themselves extremely clever for naming The Differential, and you thought, "Well, of course equations model everything. What else would they do?" and this logic would later be cited as evidence that in the time before your disorder, you did not think hard enough.
      That night, when you went out after the lecture, you held a pomegranate-flavored beer aloft and told the joke, "How does the irrational number insult the imaginary one?" but when your mouth said, "At least my I exists!", you felt that it was just a mouth speaking a punch line.
      A face smiled expectantly, waiting for laughs, then a hand faltered and caused beer to drip down a chin. These parts were all yours, but they did not feel like you.
      From that point on, you felt as if you were both watching and instructing yourself, bossing your body around. Research tells you that this condition is called "depersonalization disorder," but you tell no one, not even your therapist, Dr. Howe, who would just say, "Why do you think you feel this way?" and even though you had an answer, you didn't want her to, so at your last meeting you steered the conversation toward your romantic life, which was usually antimaterial. However, it currently seemed to be on an exponential upward trend.
      "I met someone," you said.
      "Why do you think you feel that way?" Dr. Howe prodded.
      "My pupils dilated around her, and my heart rate increased," you said. "I think that our personalities and interests represent a good statistical probability of making us a compatible match."
      "Does it feel like love?" she asked.
      "It feels like a feeling," you said. "I would say that it is a feeling."
      Everything you experienced seemed to be a field observation in a scientific experiment. You were not sure that you minded, even thought that you might be excited by your self-diagnosed rare mental disorder, because now you had an excuse for your inability to relate to the outside world.

That woman, Jodie, the one about whom Dr. Howe inquired, she called you on Sunday and asked if you would like to come over and have some Malbec, this great new wine she discovered that is cheaper because no one has heard of the grapes that are fermented to make it. "I could make a model of wine price versus perception," you said, and she replied, "Okay, bring it," as if she did not know that the model was a formula and that one line of handwritten text would not be very interesting to look at.
      As you were getting ready to meet Jodie, you should have found your ability to approximate everything with an equation disturbingly deterministic, but you did not think about it enough until later, because right then you were looking down on your body, which was standing in front of a mirror trying to choose clothing items that would convince Jodie to take your clothes off.
      After you arrived at Apartment 3A, when you knocked and she opened, you were amused that this physical meeting looked like a scene out of a bad sitcom, one that features an ostentatiously awkward protagonist, an ostentatiously quirky secondary character, and a trendy housing district.
     "Do you believe in out-of-body experiences?" Jodie asked after a third glass of wine, when people's inhibitions about mentioning metaphysics are lower than they should be. Although you knew that she was referring to new-age spiritualism, you thought that she might be the person most likely to understand what was going on in your head.
     "My life seems like one long out-of-body experience," you said, and she said, "That's hot," and put her long-stemmed glass down.
     You felt like a voyeur, a freak with an aerial webcam, as your hands moved over Jodie's body and the two of you slid around on the couch. You were creating a video of her, a memory. Was it wrong, you wondered, to watch what you were doing? If you closed your eyes would the mind floating above your body still be able to see what was happening? More importantly, would that make Jodie think you were more or less into it?
     You viewed sex differently after observing yourself in the process. You had never thought of it that way—as an act—and you knew, logically, that every action causes an equal and opposite reaction, but you did not think about that Newtonian fact as you stared at the clothes scattered on the carpet.
     "That was transcendental," she said, and curled her fingers in and out on your stomach, as if they were rays of radiation emanating from one spot in the center of her palm. You thought that her fingertips would leave marks like the shiny paths snails make when they move, as if she were polishing you. "Yes," you said, "I wish I could have watched." She laughed because she thought it was playful and fresh; you laughed because it was ironic.
     As you twirled her hair and told her she was pretty and told her the story about how you had to wear headgear for two months in third grade and said that this was the character-building experience that produced your now charming personality, you wondered how you remembered this story when your mind was busy listening to the things you said and thinking, "Nice one! She'll like that."

You were not afraid of the dark, so when you got home from Jodie's apartment, you lay in the field behind your house, looked up at the stars in a post-coital haze, and let the blackness surrounding them surround you.
      As your view lifted itself up and out of your visual cortex, you saw first the firing paths of your neurons, then the lights of Collegetown, then the incandescent glow of the world's bulbs, and then, finally, clusters of galaxies. These four images all had the same structure—long, stringy filaments crawling from dense nodes—a structure that can be explained by the simultaneous maximization of surface area and volume.
The universe was a 13-billion-light-year-wide brain, and your brain was a three-pound universe. You were comforted that, since the universe-brain must behave calculably, your brain-universe must do the same.
      No, you were not afraid of the shadows between somas and galactic centers, but you were afraid of isolation, of the space between your body and the electrical storm in your head.
      You chose to see this disconnection as a cosmic mandate from your neurotransmitters, and you fell asleep in the field imagining the y=x line of Jodie's smile, the y=x2 of her breasts, the y=sin(x) of her respiration, and the delta function of her heartbeat. You did not notice the way the oak branches were backlit by the moon, nor did you assemble the fractal sets that would model them with negligible chi-squared error. Not now. For now, for the moment, you concentrated on the speed of your body moving with the universe's accelerated expansion.

The weekend had ended, and your mental condition did not fade as you hoped it might. However, resigned to the new calling of self-documentarist, you decided to embrace this point-of-view and investigate its oddness to the fullest. So Monday morning, as you were getting ready to go into the lab, you looked down at your biological components and thought, "Knees are very strange things, indeed," before your hands pulled up your pleated, slightly tapered khakis and your legs went to work.
      When you got to the lab, the head of the Department was waiting in your workspace, which was decorated with your favorite comics, all of which exploited the humor of throwing social incompetents who speak in scientific jargon into situations with people who are neither awkward nor scientific.
      "Hey, you," the head said, to establish a tone of familiarity, and you assumed this meant she wanted something. "How's it going?"
      "Why?" you asked.
      "I was just curious," she said.
      "Oh."
      "Well, I'm fine," she said, smiling. Then, "I am writing a feature piece for The Differential, an article that profiles our beloved graduate students. Would you be willing to answer a few questions for me?"
      "Do you know my name?" your vocal cords asked, and your brain smiled when the corners of her mouth went down.
      "We can start there," she said. "Who are you?"
      You told her your name, and it sounded strange emerging from between your teeth and tongue, and you stopped to think, "I am that person. I am me," which did not seem like it should be revelatory, but felt as if it were.
      "Well, now, tell me about the moment you first knew that mathematics was the one and only one true field for you."
      Though this was a leading statement, you obliged and told her about that time on the swingset in the backyard of the first house you remember existing, the one on 112 Pascal Place, Apopka, FL, 35813, an address your kindergarten teacher made you memorize in a time when other pedagogical methods were too complicated for your neural net.
      You had begged your parents for a tree fort, and though they said, "No, it's too dangerous," you know now that they meant, "We prefer wooden structures that come with instructions," so when you came home from school on your sixth birthday and saw your father hammering away at a half-formed playground, a glossy booklet of numbered pictures weighted to the ground by nuts and bolts, you were happy enough.
      Just before dark, your father finished his construction, and he called you away from the hand-carved kitchen table where you were drawing your own solar system, one with seven planets, one in which you dictated chemical compositions and flora and then invented aliens with physical features uniquely suited to the conditions of each planet. A solar system completely different from your own, and completely determined by you. You hid the planetary drawings under the paisley seat cover and went to your swingset.
      "Is this story going somewhere?" the head interrupted.
      "Yes, of course," you said. "What else would it do?"
      The advisor continued to listen as you told her about the first time you climbed aboard your very first swing, which you imagined might propel you into some unknown orbit, though now you know that exiting Earth's atmosphere is not good for human respiration. The wooden supports of the playset leaned slightly forward and back as the swing's parabola scooped through the air. To your father, you expressed concern that the swingset was structurally unstable.
      "No, it's fine," he said. "I followed the procedure. Plus, we could write an equation that would tell us exactly how much stress it would have to be under for exactly how much time in order to make it collapse."
      "Could we do that now, please?" you asked
      Your father laughed. "I only know what the variables are," he said. "I don't know how they work."
      You got off the swing and, mumbling your thanks anyway, walked back toward the house. Having decided that it would be okay for collapses to be predictable if you were the one making the predictions, you got out the dictionary, looked up the words "variable" and "equation," and scribbled notes on definitions you didn't understand, as you could barely sum two-digit integers.
      The head of the Department tapped her pencil on her pre-printed interview form and said, "So becoming a mathematician is a step on your road to becoming a psychic."
      "I prefer the word ‘determinist,'" you said.
      This conversation was the first time you had thought about the swingset in years. For a long time, you had been able to ignore your fear of mathematical models, as you had been in control of them, forming them and testing them and tweaking them, but now, recounting a story from a time when you could not add things up and thought equations were relevant only to playthings, a horrifying truth was pushed to the foreground of your brain: the world is fundamentally knowable.
      "I have to go now," you said to the head.
      "I knew you were going to say that," she replied, and your legs had the urge to break into a run. Then you wondered if she knew you would run, so you walked, but then you wondered if she knew you were going to change your mind, so you stopped, and when you turned around she was staring at you, just like you knew she would be.
      When you went to see Dr. Howe that afternoon, she said, "How are you?" and you responded, "Paranoid."
      "And how does that feel?"
      "Paranoid."
      "Having paranoia makes you feel paranoid about being paranoid?"
      "Yes," you said, "and having paranoia also makes me feel plain first-degree paranoid."
      "Why do you think you feel that way?"
      As you explained to her that it all began with the Big Bang, you were impressed with your body's autonomy and acting ability—it could speak and behave and gesture while you felt that you did not inhabit yourself, corporeally, and Dr. Howe, resident medical expert on your brain, could not tell the difference.
      You told Dr. Howe about the swingset and how it set you to wondering about determinism, though at age six you did not have a word for it. In fact, you did not discover the word for it until age twelve, when you picked up a book called Cosmological Theories and began to read the text and ignore the equations, which were over your Algebra-One-level head. From Chapter Two, you learned that when all of the Universe's matter exploded from an infinitely dense point in space, events were preset in motion. Not just any events—all events. If you understood physics better, and if you knew the exact number of quarks and leptons, of protons, neutrons, and electrons, and if you knew the angles and velocities at which they whizzed away in the first zeptoseconds after the Big Bang, you could write equations to tell everyone how these particles would interact, indefinitely. The nebulae and quasars and blazars and pulsars and people they would become, and when, and what would happen next. And even though those three "ifs" were "if and only ifs," you know that when a tree falls in an empty forest it makes a goddamn loud noise, and so the fact that Homo Sapiens cannot predict the universe means nothing, certainly not that the universe is un-predictable.
      Chapter Two was entitled "The Subatomics Chose for You."
     "Anyway, it's just a theory," you said to Dr. Howe, though your voice has never been very good at nonchalance.

The next day, you saw Jodie again. You were not sure why you liked Jodie so much, but you did, already, even though it was only your second date. Your body liked her, which was not unusual, but you could not figure out what your mind thought about her, which was strange, because that was the only part of yourself of which you felt a part. Jodie let you relate to her on a non-professional, non-academic basis, and she liked fractals (even if her interest stemmed from psychedelic art), and she did not laugh at things you would have laughed at before the disorder, such as the terms "out-of-body" and "transcendental." She was open-minded, and your head was so wide open that your mind had apparently fallen out, and you thought Jodie might understand you, or at least would not mock you, which was close enough.
      She came over to your house, and you left your textbooks scattered about, as you thought these were the kinds of decorations she would like. When she arrived, she wiped her feet on the doormat that had a picture of a rhomboid pie with the text "pi r square," and she said, "I get it."
      The two of you lay down on the couch, and as you looked at her body you saw it in the way you saw your own: as a closed set of separate, silent parts.
      "These are your veins," you said, traveling your fingers along the blue highways on her arm, "and this is your wrist. Below this skin is your hemoglobin. Then your bones." You wanted to know and touch and feel all layers of her, from her skull to her appendix, the necessary and the vestigial.
      You had the urge to ingest her. To make her parts part of you. To put pieces of her into your mouth and let your esophagus contract them down into your stomach. You wanted to reach inside her torso and pull out her pancreas. Hold it in your hands, hoist it into the air and rotate it in three dimensions. See how it looked under fluorescent lights. Instead, you said, "Fractals could model your circulatory system," and she said, "I know. Trees and galaxies, too. It's all connected," and then you kissed her and you felt your lips feeling hers, and it didn't feel like romance—it felt like history, the kind that is made, and it didn't matter that billions of subatomic particles had known that this would happen for thirteen billion years, because it was happening now, to their sum. To you, and to her.
      If the living room had exploded, it would have been cosmically insignificant, but you knew it would have mattered to you, and so you allowed yourself the narcissism to admit that this living room and you and Jodie were important. Your body positioned itself parallel to Jodie's, pulled it very close.
      "What are you doing?" she asked, then laughed as your body wrapped its legs around hers as many times as they would go.
      "I want to be dense with you," you replied.
       You wanted to make your bodies so close that the only space between your skin would be the emptiness of the electrons' orbits around their nuclei. You wanted to compress the electrons' spinning, push your atoms so close to hers that your bodies would reach degeneracy pressure and turn into some kind of post-human plasma, a thing with no consciousness, no imagined agency, a thing that simply interacted, with no concern for how or why or what happened next, a thing that existed only in the present tense.

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The idea for this piece came while I was taking a class in differential equations. I was both disturbed and elated by the ability to mimic much of the world's behavior using equals signs and variables. Around the same time, I happened to hear about depersonalization disorder, and I began to read first-hand psychological descriptions. Depersonalization and differential equations became conflated in my mind, and I began writing with the intention of investigating how the two concepts were connected.