Mary, I wonder sometimes too. When ever they say we only use 10% of our brains I always want to throw up my hands and shout “Would someone please explain how I can access the other dang 90%? I could sure use some extra memory!”
On the opposite end of your question, here is a situation from a town where I used to live: There was a man in our town who used to walk around talking to himself. He could recite on demand, every part of every train that ever existed, down to the littlest nut and bold from old fashioned steam engines to superliners. I wonder if he went crazy because he COULDN’T forget anything once he learned it – and imagine your brain getting constipated with all that trivia! Supposedly, our brain moves useless information that we don’t need to access, somewhere into the far back recesses but I don’t think his could. It was sad because he threw full blown tantrums on the sidewalk and scared people pretty often. He lived in a homeless situation but did NOT want anyone to fix that.
Such a complex subject. Have heart. Many people live to very very old ages with full memory and ability in tact. We only hear about the ones who don’t and it makes it seem like theirs is the only outcome.