I was taught a bit by my dad, who has experience as a professional web designer and illustrator, and yes, as an art teacher. He taught me basic perspective and... well that's pretty much it.
I really wasn't into art all that much growing up. (In fact I detested the very artform because I had no skill in it) But around highschool I stumbled upon manga and anime, then I became a bit of a doodler.
Eventually, these doodles got gradually better, so then I suddenly got serious about creating and really began learning on my own. Now I create stuff and can draw a lot of stuff. I still have problems making whatever I want, but I've only been serious for around 4 years.