Here I go, laughing in the face of tempted fate...but I've never really had an injury
I've done the usual stuff like stubbing my toe, burns, cuts but nothing to cause a serious injury...(had a rubber removed from my nose once too but I was only 6 and that kinda thing's allowed when you're 6)
Believe it or not the most painful "accident" I've had was last year and I was stung by a wasp. I felt something fall onto my hair so I put my hand up to my head (without looking) and ended up picking the wasp up between my fingers...turns out they don't like it when you do that...
My most stupid injury was a few years ago, walking through the high street on my way to the school I was working at. Had a big bag on my left shoulder and the strap fell down, so I reached up with my right hand to pull it back up, which is perfectly normal except that my right hand decided to smack itself into this absolutely hideous metal dog statue I was walking past and I ended up in A&E with a severely briused hand, though I think the humiliation probably hurt more!