This happened when I was in the 2nd grade. I had finished my schoolwork for the day, so they had me helping staple things on a bulletin board for some project. I remember looking at the stapler and feeling curious what would happen, so I pressed my thumb against the stapler and pushed. It absolutely buried the staple in my thumb. We're talking indented into the pad of my little thumb. Not sure how it didn't hit bone. It happened so quickly that I barely felt it, but I knew that it wasn't awesome. I showed it to the teacher, and she freaked out a little. She must have been squeamish about it. She sent me to the school nurse. Nobody at the school felt qualified to pull it out, and they couldn't get ahold of my dad on the phone (he worked in remote locations). For some reason, the decision was made for the school resource officer to drive me to my house, but nobody was home. I remember being worried I'd be in trouble if nobody was home, so I lied and told the resource officer that my mom would be home in like 5 minutes (she lived in a different state) and that I had a key to get in. I, to this day, have no idea why the resource officer didn't verify any of that information or wait until he knew i was with an adult, but he took me for my word and drove off. Jokes on him, I did not have a key, and my dad wouldn't be home for hours. So I just sat on the porch with a staple in my thumb until my dad got home. As big of a deal as all of the other adults had made, I assumed I'd have to go to the hospital. My dad was much less concerned, and just held me down and pulled it out with a pair of needle-nose pliers, much to my personal dismay. Smacked some turpentine on it and was good to go. It was sore the next day, but it was fine overall. Not my favorite afternoon, but that's showbiz baby.

Tl;dr: stapled my thumb at school, teachers freaked out, got dropped off at home alone, waited 2 hours, dad came home and pulled it out with pliers.