Were to start. I do a lot of stupid things and learn from retrospective reviews. The trip to the clinic ones are extremely rare, fortunately. Mostly they just involve me going around saying ow ow ow for a bit or patching them up with a band-aid. So, how about a leveling-up short list?
Not going to the clinic worst two.
Being hit in the head with a train. Yup, I was picking up something at the side of a freight track while a freight train was slowly rumbling along it. I cought the sight of a step coming at me and leaned back just in time to be hit in the forehead with it. It went BONGGGGG! no kidding, the two I was with thought it was hilarious. So did I. Pulling back fractions of a second later, it would have killed me.
The bicycle crank incident. For some reason, I decided the ultimate tool to remove the retaining ring from the crank case would be a driving rod and a heavy ball pein hammer. Through some feat of uncoordination I managed to bash my thumb with the hammer really hard. I felt like I was going to vomit, stumbled around, and went to the bathtub, ran the thumb under warm water, and put a wet, cold towel around my head, fought passing out for around an hour.
Escalating to visiting the clinic.
The roto-tiller. After rototilling a lawn for new earth and planting my wrists hurt. The next day they hurt a lot more and were swollen. I went to the clinic and found out they were sprained. A week of anti-inflammatories and wrist supports followed. Do not till too deep at any one time. Lesson learned.
The mighty hammer. Tennis elbow, anyone? Sounds funny, but it hurts like hell. I was driving in roofing nails for an afternoon with one hit. It was fun, but came with a painful price tag and a trip to the clinic.
The heavy toolbox. This thing has everything needed to repair anything in a house it weighs around 25 pounds. For some reason, I decided to through safety to the wind and become a stupid monkey. I leaned to the side and with one hand took hold of the toolbox and lifted it off the floor, straightened up, lifted it to the workbench all in one motion, and went on to repair, I think it was a sink. I felt a bit strange, had dinner, walked the dog felt more strange. Lifted the toolbox off the bench, put it back underneath. By this time, the strange feeling had become very uncomfortable. The next morning I got up and started my day. I went to mop the floor and couldn't lift the bucket out of the sink, ouch, so I started walking to the hospital. I found myself waving around like one of those air blower wavey stick men. Yes it hurt a lot. A bus stopped and gave me a lift. I spent 3 days on my back taking muscle relaxants and 3 more getting back on my feet.
Those are the worst to date. To be fair, all of these happened in my teens and twenties.