You Know What's Dumb? A Work In Progress

A growing list, in no particular order:

1) Going to Mount Everest
2) Taking selfies on cliffs
3) ATV driving
4) Leaving things in cars. Things you will miss if they are stolen. Even you, A-Rod
5) Dodgeball
6) Running the bulls in Pamplona.
7) Base jumping. Even for science.
8) Getting off the boardwalk / pathway near sources of geothermal energy (volcanoes, geysers)
9) Getting in a rocket you built in your back yard
10) Puppetry of the Penis  
11) Photographing wildlife close up in state parks

12) Challenging the world land speed record when you're 69. Everybody knows your reaction rate slows when you're old.

13) Flying in vintage planes

14) Trying to retrieve your phone by climbing inside the stegosaurus statue where you dropped it

15) Gender reveals.

16) Balcony gymnastics

17) Rich people space travel

18) Shipwreck looky-looing

19) Feeding supermarket turkeys to predators in a swamp

I can't feel sorry for you if you're going to do stupid stuff.

Bonus points for death or serious harm while selfie-ing.

Is it a sign of age that this stuff is getting on my nerves? When you know that things are ill-advised and you make the choice to do them anyway, I'm not going to feel sorry for you after the bad thing happens.

Updates:

I just added dodgeball. It's mean. 

Space travel was suggested by That Nice Boy, and I heartily agree

People who go looking at the Titanic and then have to be rescued. Waste of money