Electricity. I got a very mild shock once and decided I just don't ever want to fuck with it in a way that will kill/maim/injure me.

wild animals... all of them.

i will not touch them, will not interact with them, etc..

i enjoy seeing them (they are cute, majestic, etc.), but i leave them the fuck alone.

Drinking alcohol while taking medication I was not supposed to drink alcohol with. Was a fun night until the alcohol poisoning happened at least!

Jumping off cliffs into water.

Broke my back. Never jumping off anything again. Very lucky didn’t get paralyzed. 9 months physical therapy and still weird random pains 2 decades later

Electricity, crossing the street not in designated place, reading instructions on household chemicals, eating raw food, eating unripe fruits. Basically everything that we teach children not to do. 🙃

Living creatures.

When I was a small child like 4 or 5ish I poked a cat in the eye (dont recall if intentionally) and he scratched my face immediately. That day I learned what karma was. Always believe that if Hurt someone or something they may hurt you. That's why I give snickers to the crazies at work.

Heroin. My childhood friend's mum let him try some when he was about 13. By 15 he was tricking for smack. By 17 he'd got AIDS and died from suicide. I supposed I watched my friend find out, but his mother really ruined his life.

Riding a motorcycle.

Condoms and safety pins

Alcohol

Geysers.

I stuck a finger in a geyser-adjacent hot spring to see how hot the water was, and my finger burned for three days. Don’t fuck around with geysers, y’all.

I've inhales acid fumes a couple times and every time it's a hard lesson to not do whatever I just did. Unfortunately it's a pretty common hazard in my line of work.