The bad news is that you've got a problem that chimps don't have. From an article in the Wall Street Journal:
Human brains shrink as people grow old, unlike even our closest animal relative, says a new study in the Proceedings of the National Academy of Sciences that highlights what researchers call the unique character of human aging.Go read the whole article to get all the dismal details.
The human brain normally can shrink up to 15% as it ages, a change linked to dementia, poor memory and depression. Until now, researchers had assumed this gradual brain loss in later years was universal among primates.
But in the first direct comparison of humans to chimpanzees, a brain-scanning team led by George Washington University anthropologist Chet Sherwood found that chimpanzees don't experience such brain loss. From that, researchers concluded that only people are afflicted by this oddity of longevity.
Unlike chimpanzees and other primates, elderly humans are prey to a host of neurodegenerative diseases, such as Alzheimer's disease. Researchers hope that by understanding the basic biology of the brain, they can devise ways to treat or postpone the harmful mental effects of age.
Great! So I get the joy of comprehending my place in the universe, but the price I have to pay is a slow descent into dementia as I get older. I love the sense of humour of Mother Nature.