Well we used to fish at a river that ran through a nearby park with a bunch of playground equipment. On our way back he decides he wants to have a smoke real quick, and there was nobody around so he just sat on the tire swing and lit one up. Almost as soon as he did, I went all troll mode, took a running start and pushed the fucker as high as I could, and kept going. He was pissed off/freaked out and kept screaming for me to "STOOOP FUCKER!!!", while I kept trying for my goal to make him swing higher than the bar at the top.
I don't know if I miscalculated the trajectory or just didn't step aside in time to go for another push because I was laughing so hard, but the next thing I knew I was waking up several feet away with my cousin standing over me looking scared as hell. Must have looked pretty bad for him not to be laughing, lol. Had tread marks on both my jaw and upper chest, and a nearly perfect purple chain pattern running up my face.
I also weighed near 220 at the time (hover between 150-160 now walking) so it must have been a hell of an impact for me to wake up as far away as I did. When I woke up I was completely out of the sand pit around the swing and a few feet into the grass. Can't believe nothing was broken.
Between my own experience and this thread, I've come to realize that nobody who KO's themselves are innocent. It seems to exclusively happen to dicks and morons who have it coming, lol.