Sherlock Holmes had an encyclopedic memory for things that were of interest to him and his work. But, Watson noted, he was studiously ignorant of many other things that were to him irrelevant. Holmes thought of the mind as a library with only so much capacity, which he wished to reserve for items of meaning.
On a lower level, Kelly of “Married With Children” had limited memory capacity. Her brother Bud noted that when she was full, any additional added fact meant that one would fall out... she’d forget something to compensate. Like “who scored four touchdowns in a Polk High football game.” FIFO.
I surrender!
Overtime? Heck ... why even risk it?
I believe my daily grind of mathematics keeps my brain moving...but remember...it's still just manipulating 0-9.
On the other end, I do historical research which is a massive puzzle. Difficult but it's all connected somehow. I follow the people via maps. I know who was the neighbor of whom...the wives and the kids and the stream they fished in. Fun but what a ride.