Oh, so many. I was such a clumsy child, and even when I wasn't being clumsy, things happened to me. It's a miracle I've never broken a bone.
When I was 11, a friend and I were sitting on my grandmother's porch, and a couple of the neighborhood bullies walked by and stole his Razor scooter out of the yard. I ran after them, catching up before they could get ten feet away (and scaring the crap out of them, which was hilarious). They dropped the scooter and took off, but I was moving too fast to stop. I stepped on the edge of the scooter, did a mid-air somersault, and landed on my back. Did I mention I was barefoot? Yeah. Sliced one of my left toes nearly to the bone, therefore proving the accuracy of the name of the scooter. ...I'm still a little miffed that it healed without a scar.
When I was 8-ish, we were coming back from a restaurant, and I had a glass root beer bottle in one hand. While we were going up the steps, my grandmother lost her balance and knocked into me, making me drop the bottle. It broke when it landed, and the glass bounced up and hit my elbow. Nobody believed me when I told them what happened...until they saw the blood XD It was a pain not being able to bend my elbow--on my dominant arm!--until it healed. I still have several scars, but I tend to forget about them since I can't see them unless I look in a mirror.
And then when I was 15, I was moving my turtle's terrarium and scraped my arm on the corner. I would have ignored that, since it didn't hurt that much, but the next thing I knew blood was dripping off my fingers. I hadn't even known it broke the skin--but it took several minutes and a probably inadvisable application of a liquid bandage to stop the bleeding (inadvisable because it said not to apply to bleeding wounds XD). It left a scar about an inch long.
And that's not even all of the most memorable stories. I just didn't want to write a novel XD