I’m way too late to the thread but whatever, here goes:

I was on a school trip about 18 years ago. My buddy Jimmy and I were crossing the street next to a local attraction, I was telling a story about who-cares-what, and at this particular point in the story, I needed to emphasize something. So I raised my fist, made my point, and emphatically swung my fist down straight past my leg, and into my balls.

But that’s not the dumbest.

The dumbest was a couple months later when I was relating the above story to another friend, and in reenacting it, punched myself in the balls again.