Thanks for the list idea!
1. Sleeping in the woods without a tent when it's raining
2. Cold shower
3. Don't change your clothes for a week
4. No shower for a week
5. Camping with limited equipment for a week
6. Stay in a super cold room for as long as possible
There was a Mr. Beast video about this.
7. Only eat rice and beans for a week
I think that's what Tim Ferriss mentioned.
8. Only wear a sheet over your body for a week
And you have to go out. Can't just stay inside.
9. Week-long martial arts workshop
10. 3-day fast (or 7-day fast)
Peter Attia recently said he changed his mind about that type of fasting because he lost a significant amount of muscle mass over the years because of it. So, not sure about this one.