Janet Asimov writes:
“Now that “aging brains” have been much in the media, I am sure that most people understand the adage “use it or lose it.”
Without working brains we humans are hulks of protoplasm without purpose or joy. Of course, a lot of people with supposedly intact brains also seem to lack purpose and joy, but I can only urge them to get some through writing. “
Read the rest here.