I nearly drowned in a pool as a kid, my school would take us for swimming lessons and at the end of term we were allowed a 'fun day' where we could play with these floating mats, water squirters and things. Anyway, i was a bully magnet for a variety of reasons and they decided it'd be fun to float these big mats over top of me after I'd gone under the water, I ended up blacking out, luckily a lifeguard noticed the kids doing whatever they were doing and must have got me out, that wasn't fun.

I once swapped a power socket out after turning the wrong circuit off, turns out it was live the entire time.

Only other one i can think that would qualify was cycling back form town I was going down a hill and my front wheel slid out over a slick manhole cover, I face grated the road becoming a meat crayon. From a neerby factorys cctv it looks like I lay there for a bit before getting up, jumping back on the bike, cycled at least a mile back before a kind stranger took me to hospital when he found me slumped over on the bridalway. If I wasn't wearing a helmet that day i really don't think I'd have moved from outside that factory. I ended up in hospital with a broken jaw, a few large gashes on my chin and shoulders, nerve damage and loss of feeling in my face and a concussion. I was wairing a helmet then but I make extra sure to put it on now and to not go zooming down hills at stupid speed.