I had the great pleasure of meeting Mr. Carmack recently (here's the photo proof: http://jacoblear.com/carmack.jpg ) and was able to listen to him talk casually, as opposed to in an interview or speaking event. He doesn't turn his brilliance on and off, it's there all the time.

When I was a kid, I wanted to do 2 things, make video games and go to space. Here we have a man who is a legend in the games industry, and also started a company sending rockets into space. He's awesome.