A look back and a look forward with one of the most successful tech entrepreneurs of our time.

With Microsoft (MSFT) turning 50 this year and a newly released book about his life called “Source Code: My Beginning,” it’s no surprise that many want to take a deeper look at what makes Bill Gates tick.

It’s a life Gates, 69, shares in “Source Code,” which chronicles his upper-middle-class childhood in Seattle up to the very start of Microsoft in 1975 alongside friend and co-founder Paul Allen. The book has a few stories that would may as a surprise to Microsoft investors.

“Yes, that is correct,” Gates told Yahoo Finance Executive Editor Brian Sozzi on the Opening Bid podcast when asked whether an older Allen gave a younger Gates the drug acid to try as a teen.

Added Gates, “Paul was responsible for all sorts of things. I mean, my first time I got drunk, the first time I smoked marijuana. You know, he kind of got a kick out of seeing my kind of zany high energy and you know, how it might be influenced. I gave that stuff up pretty quickly because I like my brain to be working.”

In Source Code, he credits his highly supportive parents, Mary and Bill Sr. — especially his super-organized and goal-driven mother — for a large part of his success.

“If you had to pick one person who shaped me in my desire to please and succeed, that’s absolutely my mom,” he said. “My parents were both amazing, but my mom was around all the time telling me to fix my manners and to get dressed and be on time.”