The best way to take a punch is to look at it. Honestly. Someone could hit you with the hardest punch that they have, but as long as you see it, it's not going to knock you out. It's the punches that you don't see that knock you out. So you could get tapped with a small punch, but if you don't see it, you're out.
I was painfully shy for a long time. I mean, that's something I really had to work my way out of. And I really think it was because, after the 2008 Olympics, I spent a whole year bartending. It was the one thing that really forced me to be just not so scared to start conversations with strangers.