I (almost) met Patrick Collison at a conference a month ago where he gave a talk. He seemed extremely smart and interesting and I had no idea he was rich and famous. So after he gives his talk, I stand in line to get his phone number to see if we could meet up sometime so that I could pick his brain. While I was in line to talk to him, I mentioned to the guy next to me "Man that guy sure is interesting", and he said "Yeah, most billionaires are pretty smart".
I was floored that Patrick was a billionaire, and then got super nervous and exited the line.