Dumbest thing you've ever done playing a game

[DK]

Mine is playing Tekken using the Guitar Hero guitar to control my characters.

I think yours is failing to kill me in GunBound for like 10 turns when I had roughly 7 health left on a single pixel of space so I couldn't change my angle to fight back.

That would have been if it wasn't for the fact that every time we've played since then i've rode you bloody.