How about just being a complete idiot?
Had just finished washing my dirt bike (KTM 520 EXC) in my driveway and like usual, I started it up to dry it off. No problem so far. Next up is to drive it around the block to dry it off a bit. I usually grab my helmet and gloves for this, but for some reason I decided I didn't need to (mistake #1).
So I get on the bike and ease it out of the driveway. Ahh, what a beautiful day! Somewhere in the next millisecond, my brain decides that I MUST do a stand-up wheelie down the road.
My first ever!
With no helmet and gloves on. Just like I had seen my buddy do out on the trails recently (mistake #2).
I'm still in 1st gear (2nd gear would have been better - mistake #3), and I crack the throttle (mistake #4) instead of just easing it on.
What the hell was I thinking?!!!
Anyway, the front end came up way fast. I do remember thinking "holy shit that front end came up fast!" as I chopped the throttle right before I looped it.
Next thing the front end came crashing down with me and the bike leaning slightly to the right. My right foot came off the peg as we went down and the bike and I proceeded to bounce of the pavement in a shower of sparks and noise.
As I got up I realized that I wasn't seriously hurt and that my melon had somehow managed to not bounce off the pavement. I then noticed our 7 yr old neighbor kid staring at me with eyes as big as plates and her mouth hanging wide open.
After assuring her that I was alright, she proceeded to lecture me on not wearing my helmet.
I did manage to get the bike back in the garage and my hand and knee bandaged up before the wife and kids got home though.