At 93, so deep in dementia that she didn't remember any details of her life, my mother somehow still knew songs.

In 1964, at the age of 39, Flannery O'Connor died from complications of lupus. She had lived with this autoimmune disease for 14 years, primarily confined to her mother's farm, Andalusia, in Milledgeville, Ga.

I became demented overnight. Sudden onset is one factor that distinguishes my form of dementia from the more common form associated with Alzheimer's disease.

When Beverly and I got together in 1992, and I moved to be with her in the little round house she'd built in the middle of 20 acres of woods near Amity, I found myself immersed in a natural setting that I responded to with all my being.

Dementia resembles delirium in the same way an ultra-marathon resembles a dash across the street. Same basic components, vastly different scale. If you've run delirium's course once or twice in your life, try to imagine a version that never ends.

In question-and-answer sessions after a reading or during an interview, I forget the question if I'm giving too long an answer. And at the end, I can't remember any of the questions. The more anxious I am about remembering, the more likely I am to forget.