My only real injury was years ago struggling cutting something with a hobby knife and the blade slipped off what I was cutting. The blade went pointy side first into my index finger to the bone. My finger grew about twice in size and I nearly passed out a few times. I have a nice little scare from that fun.
I also remember another fun event years ago that didn't include me getting hurt (some how) but it was very memorable. I had a timer charger that I used to lock on fast charge with a screw so I wouldn't have to keep cranking it back to get a full charge. Well one weekend morning I cranked it back on fast charge with the screw on and had to hurry off to a day trip the family was going on that I knew nothing about and had about 3 minutes to get ready for. So when I got back late at night from the trip, I walk into my room... The plastic around the battery (it was a stick pack) had just about melted all away and the battery was sizzling into the rug. So with a "Oh @@@@" I unhook the battery and carry it running down the stairs. I couldn't throw it out the window because there where screens on them that were a pain to take off. So as I am carrying the already hot battery down the stairs that now has no structural rigidity it starts to short with sparks, smoke and even a bit of flame from the cells hitting each other. I finally get to the front door and toss the sparking smoldering smoke ball out in the yard. To which my older sister who was at the side of the doorway trying to cross the doorway watching the whole show yells out. "What the badword was that?!!" All I could do was give her a realy odd look, start cracking up and say "You realy don't want to know".