Try to keep it practical (like something that would be fairly doable, you just havent gotten around to it…yet)
There are apps that you can input text into and they can replace the characters in each word incrementally to help learn them. Wanna get into that


If you’re a software engineer, memorizing an ASCII table (particularly the hex numbers of each character code) is definitely helpful. If for no other reason than so that you can read things that are randomly written in binary without having to consult a table.
Something not really otherwise terribly useful that nonetheless helped me keep my sanity: learn how to convert to base64 in your head. At work, we had really boring 8-hours-a-day training for a couple of weeks. To pass the time, I came up with random strings to base64 encode in my head. “
Hatis48 61 7a. The first six bits are010010which in base64 is anS. The next six bits would be000110which in base64 isG.” Etc. I’d write down the base64 strings character by character as I derived them and then check my results for errors when I got back to my desk.