Verb conjugation became muddled. Which was correct? “I am a neurosurgeon,” “I was a neurosurgeon,” “I had been a neurosurgeon before and will be again”? Graham Greene felt life was lived in the first 20 years and the remainder was just reflection. What tense was I living in? Had I proceeded, like a burned-out Greene character, beyond the present tense and into the past perfect? The future tense seemed vacant and, on others’ lips, jarring. I recently celebrated my 15th college reunion; it seemed rude to respond to parting promises from old friends, “We’ll see you at the 25th!” with “Probably not!”

Yet there is dynamism in our house. Our daughter was born days after I was released from the hospital. Week to week, she blossoms: a first grasp, a first smile, a first laugh. Her pediatrician regularly records her growth on charts, tick marks of her progress over time. A brightening newness surrounds her. As she sits in my lap smiling, enthralled by my tuneless singing, an incandescence lights the room.

Time for me is double-edged: Every day brings me further from the low of my last cancer relapse, but every day also brings me closer to the next cancer recurrence — and eventually, death. Perhaps later than I think, but certainly sooner than I desire. There are, I imagine, two responses to that realization. The most obvious might be an impulse to frantic activity: to “live life to its fullest,” to travel, to dine, to achieve a host of neglected ambitions. Part of the cruelty of cancer, though, is not only that it limits your time, it also limits your energy, vastly reducing the amount you can squeeze into a day. It is a tired hare who now races. But even if I had the energy, I prefer a more tortoiselike approach. I plod, I ponder, some days I simply persist.

Everyone succumbs to finitude. I suspect I am not the only one who reaches this pluperfect state. Most ambitions are either achieved or abandoned; either way, they belong to the past. The future, instead of the ladder toward the goals of life, flattens out into a perpetual present. Money, status, all the vanities the preacher of Ecclesiastes described, hold so little interest: a chasing after wind, indeed.

Yet one thing cannot be robbed of her futurity: my daughter, Cady. I hope I’ll live long enough that she has some memory of me. Words have a longevity I do not. I had thought I could leave her a series of letters — but what would they really say? I don’t know what this girl will be like when she is 15; I don’t even know if she’ll take to the nickname we’ve given her. There is perhaps only one thing to say to this infant, who is all future, overlapping briefly with me, whose life, barring the improbable, is all but past.

That message is simple: When you come to one of the many moments in life when you must give an account of yourself, provide a ledger of what you have been, and done, and meant to the world, do not, I pray, discount that you filled a dying man’s days with a sated joy, a joy unknown to me in all my prior years, a joy that does not hunger for more and more, but rests, satisfied. In this time, right now, that is an enormous thing.

[Editor's note: Paul Kalanithi died March 9, 2015, at age 37. Here is our obituary.]