I don't even have grade 10, let alone a high school diploma. Took English 10 twice, but the teacher kicked me out both semesters. Would have a high school diploma, except Canada won't accept the two years I did in Texas and the UK. So yes, self taught.
My biggest regret in life though is not getting a mentor while needed, as I'm confident if I did, I'd be infinitely more successful than I am now. I've been able to build up good sized online operations, several times, but my pitfall has always been turning them into long-term, self sustaining operations where I'm not required for the day-to-day maintenance, allowing me to concentrate on future development and growth.
Always happens the same. Good sized growth, I get bogged down with day-to-day bullshit so future development halts, company plateaus, and eventually declines. Got another project launching right away here, which I think has excellent potential. If the growth is there, I already know exactly who I'm going to solicit as a mentor in exchange for some equity.