I just finished a college prep course. Until this fall, I'm studying on my own to build and strengthen my skills. I want to study physics and mathematics, and eventually chemistry. But circumstances suggest that programming might be a better career choice for me.
But wow! The more I get into these math and physics books, the more I love it. I never knew how beautiful and fascinating it all is. I've been dipping into Pickover's A Passion for Mathematics. That's the kind of book I wish I had back in high school.
I am taught mathematics in the sense that I take math classes and ask my instructors questions. However, most of the work comes from me sitting down reading the book and doing the exercises, so in a sense I teach myself mathematics (and the same can probably be said of most people).