Sure he went and sat in some courses but only for a limited time and only when he thought they taught something he liked, like calligraphy.
Doesn't that imply that school is but a matter of interest? So if your interest lies in building something great RIGHT NOW, wouldn't it be better for you to not waste time and money at school but rather go do something you so dearly want?
My intent here is not to discredit your post. Though I see the value in your post, I post this only to avoid you and your readers from clumping all dropouts into a category. My view is that school is not for everyone. Some people have this innate understanding of the world and thoughts so radical that school only serves to beat them into another brick in the wall. This is unfair to them and unfair of society to judge them.
Personally, I think that if YOU believe in it and if you believe in yourself, then right now is as best a time as ever. School or not. Everyone has to decide for themselves.