Remember that short story, think it was called “flowers for Algernon”, don’t remember the author. It’s about a man with low intelligence who somehow (I forget how) gets smart. But only for a while. Then he sadly gets stupid again. It’s like Tucker is on the downside of that tale!
There was a movie I think, with a different title. Never saw that.
The movie was Charly (with the y backwards) it starred Cliff Robertson. I read the SciFi novel back in Jr high. Don’t remember too much about it. I guess I wasn’t impressed.