I've hurt myself worse, relatively speaking-the worst injury in my life was a torn muscle in my side I somehow managed to do while in a car that suffered a rear end collision-but I'll tell you the stupidest injury I've had that, given the relative scale of the injury, counts as the most painfully stupid injury EVER.
Ages ago, when I had a sizable vinyl collection, I decided I wanted to listen to Peter Gabriel's debut solo album. I went to get it off the shelf it was stored on, and when I had put the album back in the sleeve the last time I had listened to it, the inner sleeve was lined up so the album would fall directly out of the sleeve. It proceeded to do this. It fell at a perfectly perpendicular angle to the floor at a shocking rate of speed, where it proceeded to strike, edge on, at the base of the toe nail of my big toe.
This doesn't SOUND painful. But within seconds, my toenail had turned purple from a release of blood, and for the next few days, until the damn toenail fell off, I could feel my pulse throb through my foot. All because I had an urge to listen to Moribund The Burgermeister.
Hurt like fucking hell, let me tell you.