What you gies do when you learn new technology and after that, you switch to some other new technology and you start to forgot to old one.

example: some times ago I start to learn nodejs and after code couple of months in it, I switch to golang but now if I look back it seems to foreign to me and I didn't create logic properly in it, unless I didn't create 1 or 2 large projects in it.

The only real solution to that is: Dont invest too much time into learning technologies that you dont plan to actually use.

Too many people feel the need to collect languages/frameworks like they are pokemon or something.

Dont focus on learning technologies. Focus on building applications and solving problems. You will pick up the tech as you go.

Every time I come back to Clojure, I basically have to learn most of it again because I never actually use it for anything other than messing around.

@LLAMS got it man, I don't need to learn everything.