Yep. I usually was ready for the ones when we were wrestling and stuff. It is the unexpected ones that take the wind right out of your sails. Hell I took a solid one in a tournament once and I still won the match. It was very tender and I couldn't walk right for a week after, but I kept it going. But man that one smack was enough to drop me straight to the ground. The guy I was talking to found it hilarious of course, as I would have as well.
Why do we find something we know to be painful to be so hilarious? Few things are funnier than a good nut shot.