Papercuts are the worst!
Once, when studying, I was changing the studied subject, and so I put down some books on the floor. I was barefoot and some loose papers were sticking out of the books. Five minutes later I became aware of an odd sensation in one of my toes. I looked down, and blood had dripped onto the floor. I wasn't even aware I had cut myself. When I had seen it is started hurting like hell, of course, as with all smaller wounds. It was weird.