I had to teach myself piano from scratch. After ten years, when I first took a formal lesson (I needed help because I damaged my wrist after practicing the opening arpeggio in Chopin's Waterfall Etude several thousand times in sequence over a couple months), the teacher told me I was horribly backwards; he generously described my technique as passable ("well, it works for you"), and my reading was more like "deciphering," but the teacher was baffled at how easily I could take a simple tune and expand and improvise on it.

I've taught friends to play piano as well. It usually takes two weeks or so before I can show them how to reverse-engineer their favorite songs, and they all bloom quickly. But there's one group I was never able to teach to be creative; those who took formal lessons as kids.

I only tried teaching a couple, so I can't generalize, but it seems like they were paralyzed by waiting for the "okay" from their teacher. As a result, I couldn't teach them that they had the gods-honest right to actually be creative. As in, being wild. Making shit up. Sounding bad. Exposure to the censure (and praise) of teachers had made them timid. It was painful.

The same friend I couldn't teach piano, though, is one of the most brilliant photographers I ever met. Pretty sure she never had a single lesson in that until she was ready.