You're saying the Russian cyrllic letters takes a weekend to learn? Maybe, that would be impressive, not for me. I think it would take me longer.

I know the Greek alphabet but only because I learned it in a frat from a YT song.

I started learning them for fun and didn't find it to be very difficult. I agree that a weekend might be a bit fast, I'd probably say a week to a month is enough time.

To practice I like going on r/EnglishCyrillic and trying to read some of the posts