I know a girl whose grandfather died at the age of 94, after thirty years of an increasingly immobile and embittered retirement. Once a rich man, most of his money had gone towards paying for the costs of assisted living and ritual dying. It had become a running joke in the family - their angry old grandfather, sitting in a chair chainsmoking and surviving on an exclusive diet of boiled cabbage and black tea, like a diminishing asset, worth more dead than alive, but grimly clinging to his television existence for reasons of his own.

He had been instructed many times by doctors to quit smoking, but he refused, not unjustifiably as it seemed to make little difference to his lifespan, only its quality. One day, denied access to sources of flame by his family, he climbed on a stepladder in an attempt to light a cigarette from the kitchen lightbulb. He fell, and was found lying on the floor with a black eye, unable to get up. "Any decent man would have died," her father said, only half-joking.

They hypothesized that, being notorious for a miser, he was holding out for the £100 that the Irish government bestows upon centenarians when they reach that mythical birthday. He'd made it to the millennium, but he must have given up on his 100th anniversary. I would have given up long before. He had no friends left alive, and he wouldn't talk any more. He shared nothing of his own life, neither money nor wisdom nor memory, with those of his family who would have wanted him to; and they in turn learned to expect nothing from him, and were glad to disregard him, glad to let him live alone in his 'home', reluctantly and awkwardly visited, alive but not truly among the ranks of the living.

She told me that when he was dying, and their family was gathered around his hospital bed, she saw her father stroke his head gently, brushing back wisps of his hair, a gesture which he would never have made in other circumstances, and I think she had a sudden vision of life and time wasted, love not expressed, people held back from each others' arms for reasons that, too late, are realized to be stupid. She saw how her father loved his own father, despite everything, and could never have told him that while he lived, or touched his head so tenderly. And if he had, what would have been different?

We are taught in thousands of almost unnoticeable ways that to grow old is shameful, embarrassing, ugly, undesirable, something to be concealed and postponed and denied by every possible means, and that to die is the worst thing that can happen to you. And yet, almost the only things we can be certain of in our physical existence are these things. We will grow old, and we will die. To allow the unconscious forces of our society to marginalize and deny us as our bodies decay from the impossible ideal of youthful beauty is to become divided against ourselves, trapped in the attics of our own heads watching our precious portraits become ghoulish and repulsive.

You can't struggle against the natural flow of life for very long. I will grow old, and I want to be happy to see my face in a mirror, and not to be told that my usefulness is past. I want to die without being forced to believe that I must shiver in terror at the coming of a welcome and temporary darkness. I don't want to sit in a bitter armchair, grimly and stubbornly waiting for the end, flicking ash on the carpets of relatives who see me as a nuisance, a paradox, like a living corpse, a ghost refusing to pass on. I want to be alive until I die.