Ouch, I hate that sort of thing in soccer... I have a soccer related fail, but I think I have a more intense one to share, so I'll save that one. Anyway, I haven't posted anything in this thread even though I've lurked it for a while just because what people have said so far is so funny. I've gotten several laughs out of this...
So, when I was around 8 years old, I was a REALLY energetic kid... so I was running around getting myself into trouble all the time, basically. Now, this time, I was running around in my living room, and there was a futon sitting on the edge of the room in what should have been an out of the way spot. However, me being a crazy 8 year old, I somehow managed to find a way to TRIP OVER the damn thing, and I went flying into a window that was on the other side of it. And it happened to be the kind of window that has a metal bar going down the middle of it, and my forehead hit that. Lucky for the window, because it didn't break, but not so much for me, because I did.
Anyway, there was blood everywhere at that point. I remember being conscious, but being in a shitload of pain, and my dad and my sister were freaking out because they probably thought I had broken my head open or something. Anyway, my mom came home later to find 4 or 5 ambulances in my driveway, and she, being a mother, also freaked out. I eventually got stitches and everything was resolved, but it still hurt for around a month.
I now wear a scar on my forehead, and get compared to Harry Potter half the time because of it. But I guess that's not nearly as big of a fail as the injury itself. I have more recent fails, but they're less intense. I may post one or two later though.