My father died of a heart attack. He was with my mother, on his way home from a concert and dinner with friends, and he collapsed in the marble lobby of their building. There was no preparation. There were no last conversations.

In the weeks afterward, in early 2006, I found myself wanting that last conversation. But what would it have consisted of? We didn't have a stormy or vexed relationship; there were no tangled resentments to sift through. He knew I adored him. So what was there for either of us to say?

When he died he was worried about the state of my marriage. He had seen things that made him think that life in our loft apartment was bleak. I wish I had told him that I was leaving. He would have been more peaceful. He could have stopped worrying about my daughter and me. I am not sure why this is important, as dirt is hitting a coffin. It is though. It is important.

Months later, I began writing a book about writers' final days. Talking to my subjects' families and friends, I realised that while nearly everyone has a fantasy of a "last conversation" with someone they love, very few people actually have it. It is the fantasy of resolving all conflicts, of emotional catharsis, that rarely ever comes to pass, because the habits of reticence or resentment that were there the whole time are still there, because the proximity of death does not transform personalities, or compel us to cut through to the heart of things, however much we want it to.

Even in a drawn-out death, when there is technically plenty of time, the last conversation usually materialises only in parodic form. Take Susan Sontag's mother - with whom she had a very knotty relationship - whose last words to her daughter were: "What are you doing here? Why don't you go back to the hotel?" Instead of an elegant ending, most of us are left with this unruly irresolution, this muddled cutting off.

I talked about John Updike's death with his former wife, Mary. She told me there were questions she wanted to ask him that only he could answer. I heard this over and over. There were questions the bereaved wanted to ask. There were mysteries or confusions that could be cleared up if only they could have engineered that last conversation.

Updike actually wrote about this. In Rabbit At Rest, as Rabbit Angstrom lies dying, he sees on his son's face, "some unaskable question". Rabbit feels sorry for everything he has put the kid through, his various ebullient and destructive flights from the family, for instance, but he can't quite muster that thought into words. His son looks at him expectantly. The last conversation is perhaps just the feeling that there is something more to say.

Most of the time these lingering questions are large and painful; they are too big for answers, there is no answer that will satisfy or salve. The promise of forgiveness, of explanation, of a few words that will repair or redeem or transform the past mostly eludes us. In a way, this is a secular last rite that we are imagining; confession and absolution, the admission of wrongs and forgiveness, church mingling with therapy to make a proper ending out of pointless loss.

There is very little likelihood that Rabbit could explain everything he put his son through in a way that would bring him peace. Peace like that can't be forced or summoned. Not to mention that standard features of many deathbeds - pain, drugs, fear, physical weakness - work against this prospect of focused insight and sudden eloquence.

We have an idea that when someone is dying, a new, honest, generous space opens up; that in the harrowing awfulness of dying there is a directness, an expansiveness, a loosening of inhibitions, the potential for things to be said that could not be said before. But if one does manage to pull off a last conversation, what can it be but a few words in a lifetime of talk? How can it be enough?

My father, a psychoanalyst, was reticent, even outside his office. There were many shadowy periods in his own life he would not discuss. He was the kind of person who, when pressed to take us to the place where he grew up, in Flatbush, Brooklyn, drove us the 40 minutes there but when we reached his street, accelerated, so the row of attached houses passed in a blur.

I had, for a while, the outlandish idea that I could have sat down with him before he died and asked him questions, with a tape recorder: whether he thought his mother killed herself or fell out the window; what happened when he and his family were evicted in the Depression; what it was like to be in the Battle of the Bulge.

But, of course, even if I had gathered the courage to ask him all these questions at the end of his life, he would have found a way to deflect them as deftly as he had at other, less dire, periods. He would not have been rendered suddenly chatty and confessional. He would have been his quiet self to the end.

Even the writers I was researching - people who lived in structure, plots, words - mostly did not find their way to conversations that offered a satisfying ending. They left things messy, unresolved, dangling.

Part of the problem is that some silences are too wide to narrate. Words, even if the right ones miraculously presented themselves, would not be enough. The confession and forgiveness we want to fill the room do not spring up more naturally in extremis, under duress. It may be the last chance for the dying person to clarify, but clarity doesn't necessarily come. In this way, death is a lot like life.

NEW YORK TIMES

•Katie Roiphe is the author, most recently, of The Violet Hour: Great Writers At The End.