I’ve been thinking about constricted spaces lately, those crammed, no-exit corners that make us feel diminished in some way, wishing to expand, to break free. In New York, you fit yourself into these spaces daily. They have a way of dictating the very procedure of your mind: the segments, the modules, the shortcuts you think in. Adjustments are made. Your thoughts become the size of the bus seat you occupy—concentrated, balled up. In the subway we press together like guests at a doomed cocktail party, alienated from one another and acutely attuned. We grow increasingly introverted as more riders pour through the doors. A shoved woman complains loudly; a man down the aisle allows himself a mild explosion. “I could be bounded in a nutshell and count myself a king of infinite space,” says Hamlet. But is this really the way it works?

A strange fever was what got me thinking along these lines. It crept in on me so subtly I didn’t recognize it at first as a fever at all. A pleasant aura of aimlessness overcame me. I was unusually entertained by myself, walking dreamily around the city—aflame, calm, tearful in a celebratory way that in retrospect, I realize, should have alarmed me. I squandered my time thinking about people I didn’t know: the man on my street with a camel-hair fedora and a tiny Havanese dog named Salvador Dalí; the woman I overheard deconstructing her stand-up comedy act with what seemed to me hypercritical brilliance. “I blew the emphasis. I spit it out too quickly. I sapped the blood from the punch line.” For days I searched for the blood in people’s speech, oblivious to what they were actually saying.

A friend suggested I see a therapist. “You may be on the threshold of a psychic breakthrough,” he said. “The least you can do for yourself is identify what it is.” I impulsively took up his suggestion, making an appointment with the analyst he recommended. The whole setup seemed like an elaborate form of constriction: the white-noise machine in the waiting area turned to maximum volume so the soul-searching in the adjoining offices couldn’t be overheard; the narrow ground-floor room where my own confessions were delivered; and, most of all, the prompted monologue about what was going on in the nutshell of my mind. About himself, of course, the therapist revealed nothing, which, in light of my intensified interest in strangers, suited me just fine. I worried about what I imagined to be his carelessness with himself—on one occasion he wore a torn sweater and his pants pockets were turned out like he had just been frisked or robbed. Kindly, he sought ways to dignify my vapors, trying to imbue them with a transformational quality, a sense that I was busting out of “old structures,” weaving a new cocoon. I thought it less promising than that. The fever (though I didn’t know yet it was a fever) had me wavering tenuously above the reasonable world. When I told him that nothing made sense, he quoted Yeats. “Now that my ladder’s gone / I must lie down where all the ladders start / In the foul rag and bone shop of the heart.”

The fever spiked. I finally took my temperature and was astonished at the reading: 104 degrees, 105, and higher. Clinging to the idea of a privileged delirium, I continued to work on a book review I owed, about the psychological mysteries of early childhood. I heard myself crooning Jacques Brel’s song about childhood: “It’s all that hasn’t been written down.” Yet it is the segment of our lives that we are most driven to recapture in words, constructing an avalanche of events that are crucial to our innermost belief about ourselves but that never took place in the way we remember them, if they happened at all. The newborn exists in a state of heightened constriction, barely able to move. With more neural pathways in operation than during any other phase of existence, however, he may well inhabit a spaciousness that is unimaginable to adults. The mystery is the amnesia that surrounds it. The fever—“my” fever, as I later thought of it—seemed to be filling in the gaps. I dreamed without terror of infancy and death, in the grip of a strange, and possibly diabolical, contentment.

After three or four days of this I dragged myself to the hospital. “You’ve got the same infection that killed Jim Henson, the puppeteer,” said the doctor. “We call it the flesh eater. Why in the world did you let it go on for so long?” I laughed, thinking it a joke, even after I was informed that the antibiotics dribbling intravenously into my bloodstream were my “best and only bet for staying alive.” The antibiotics took away the dreams, and the world shrank to what was in front of my eyes: the fire-retardant ceiling tiles, brown at the edges; the misfit ventilation plate with its gold paint flaking off. I felt like Beckett’s character Malone on his deathbed. The sense of restriction seemed to expand to everything. When physical space contracts, the mind grows outsize, driven to manufacture what isn’t there or to stifle what is—the chief agony, perhaps, of being in prison. Tony Judt, who suffers from the motor-neuron disorder known as Lou Gehrig’s disease, describes it as a kind of “progressive imprisonment without parole.” The paradox is that as autobiographical memory sharpens, muscle memory diminishes to a set of impotent sensations. “The pleasures of mental agility are much overstated, inevitably—as it now appears to me—by those not exclusively dependent upon them,” Judt writes.

The young man in the bed next to mine could not bear the confines of our tiny room. He had been admitted after a crack-induced heart attack. Revived, he found himself in an agitated state of cocaine withdrawal. He paced the room, cursing, energy spilling out of him in an uncontainable rush. Ducking into the bathroom to smoke a cigarette, he set off the alarm. He addressed me as “sir” in a sinister manner, then tried to divert my attention in order to swipe my cell phone. When that failed, he said, “I got to call my uncle. To apologize. You understand?”

My mother phoned each morning. “Have you gotten worse? Don’t try to protect me, Michael. Are you sure you’re not worse?” The friend who had recommended the analyst came to visit. “You look terrible,” he said. “He looks terrible, too,” he added, referring to the crackhead. I pointed out that we were in a hospital. “It’s not a fashion show. Have some manners, for crying out loud.” I forgave his satisfaction at not being one of us and for asking prurient questions about my prognosis, flaunting his good health. During better times, I had felt the same impulse among the sick.

After two weeks, I was sent home, congratulated for surviving. “My compliments to your constitution,” said the doctor. My friends remarked at the weight I had lost but for the most part didn’t believe I had really been sick. I looked pink and hale, my skin eerily spotless from the bombardment of antibiotics. I seemed different to myself, but not different enough. I loved the street, the sun, the garbage, the river, the smell of gasoline and cheap stale beer. Even the quacking car alarms under my apartment window couldn’t annoy me. After a while, however, I returned to the familiar neuroses of health, tarring my days with their quota of misery, as if it was part of a balanced diet, the psychic broccoli that had to be eaten.

Relieved at my recovery, my mother told me of her decision to be cremated. She would not be buried in the Jewish cemetery next to my father, where a plot for her had long been reserved. “Who bothers to go stare at a headstone?” she asked. The saleslady from the crematorium admired her outfit, then presented her with the urn that would eventually contain her ashes. “Does it need to be this big? I’ve nowhere to put it. She could have waited. It’s really quite vulgar.”

Less than three weeks later she was discovered to have an inoperable tumor. I was at the hospital again, a tourist this time in the small boxy space of illness, holding on to her life in a way I had not thought to do with my own. My brothers and I sat in a tight circle around her, like disciples. Her entire life she had been a bulwark against disorder, unfailingly fixing herself up before going out or receiving a visitor, dressing to the nines. Now, unembarrassed, she offered us her ailing self without adornment, worrying about our children, gossiping about the doctors, deflecting our fidgety attention while enjoying it as her due. No longer able to eat, she reminisced about her favorite meals—a coq au vin at a communal table in Provence in the 1950s, a fish stew in Bangkok, a roasted lamb in Istanbul, a lobster roll in Rockland, Maine. She encouraged us to give accounts of our own recent meals—“even if it’s just a tuna-fish sandwich”—as a newly blind person might ask for a description of his garden.

She was vivid and elegant, her eyes glowing with uncommon alertness. Malone, in a similar condition, said: “My need for prettiness is gone. . . . Something must have changed. . . . I shall not watch myself die, that would spoil everything. Have I watched myself live? Have I ever complained? Then why rejoice now?”

The Accidentalist is a new column by Michael Greenberg. He is author of the memoir Hurry Down Sunshine (Other Press, 2008) and a collection of essays, Beg, Borrow, Steal: A Writer's Life, which will be published in paperback this fall by Vintage.