I would consider myself a self-taught potter. I only had 1 class in college of formal training. I picked it up just like that. Centering, throwing, and pulling walls was very easy for me. After earning a bachelor of fine art degree and concentrating on a career in graphic design, I returned to the wheel after several years being away from it. I took random classes at different art centers and through continuing education programs just to use the studio equipment but I didn't really have any further instruction.
I think all potters are self-taught at some point in the process because there is so much trial and error and good-guess work.