My dad is a doctor who works in Aged Care. He has treated hundreds of dementia patients. It seems very strange which patients get dementia vs which ones don't. Some young people get dementia (early onset Alzheimers') and some old people live to 96+ with a sharp mind (see David Attenborough and Queen Elizabeth).

Part of me wonders if there is a psychological aspect to dementia. If it's a way for patients to cope with thanatophobia? When people age the spectre of death inevitably looms larger and larger. What if dementia was a form of denial? Not intentional, but a way for the brain to cope with the fear of death, by forgetting one's surroundings, until the fear of death is annihilated?

I would love to see studies about how dementia and thanatophobia are linked (if at all). I could and likely am on the wrong track. But I am surprised no one I've seen has ever raised this question.