If we want to keep this thread alive, refrain from merely stating a skill and be on your way. Elaborate on why you're learning it, what you're gonna use it for etc...
I'll start, I'm teaching myself how to improvise cocktail/jazz piano, cause that's the only thing I haven't managed to develop the skill for when it comes to playing the piano.
I'm also starting to teach myself (online and stuff) how to develop games. I know how to code, but I haven't had practice with game engines, starting off with unity and gonna work my way up from there.