Do hobbies fall under this? Like writing, drawing, painting... things like that. The only formal "training" I've had in any of these was during high school, in the form of one advanced placement studio arts class, so I guess I count as self-taught even though I've always wanted to go to art school. I've downloaded a bunch of Gnomon workshops though but never got around to watching them. Oops.
For the first half of my life thus far, I could only whistle by inhaling. Apparently everybody else does it the opposite way. After trying for a while I finally figured out how to do it the normal way... and for the longest time I couldn't figure out how to snap my fingers, then learned with only my left hand, which makes me feel pretty dumb now that I can do it with both hands pretty easily.
But back to artsy things, I really want to mess around with encaustic stuff next. Maybe one day I'll teach myself how to work with oil paints - right now I just do watercolors and acrylics, but even then there are so many techniques that you never really stop learning