I was "home educated" - the typically British middle ground. Not "home school" (school at home) and not unschooling. But self-educated / family educated at home, for the whole of highschool level. We'd just moved country, and didn't want to jump into a new school system straight away. It worked pretty well for us. I spent a lot of time learning to program and play music, I joined a local drama group, played in the ch…
Just like me. I learned it around 13, because I wanted to figure out how to rotate sprites and move them around other sprites; I remember spending long hours looking at a math book and drawing pictures with a pencil. When I finally grokked the proper transformations, I was extremely excited, and I remembered that math forever since. Pretty much every other thing I learned for game development I understand well and remember 'till now.