Reuters
Questions ranged from asking whether his Thiel Fellowship has been a success (answer: yes) to who his favorite rap artist is (answer: Ben Horowitz, who is known to love rap and hip-hop music).
Some questions, however, actually were in regard to his business acumen. Reddit user papabearshoe asked, "Peter, what's the worst investment you've ever made? What lessons did you learn from it?"
"Biggest mistake ever was not to do the Series B round at Facebook," Thiel answered.
Of course, Thiel made an angel investment in Facebook of $500,000 for 10.2% of the company and a seat on the board.
But it looks like he wishes he would've invested a little bit more. "General lesson: Whenever a tech startup has a strong up round led by a top tier investor (Accel counts), it is generally still undervalued," he wrote in the AMA.
"The steeper the up round, the greater the undervaluation."