What are some most important things a man has to learn when he is in his 20s?

6 skills every man in 20 must possess

1. Basics of relationships, true nature of girls like hypergamy and pragmatism (Its inbuilt in them and they can’t help it.)
2. Basics of female psychology to deal with their shit tests and subtle mind games. I pity at fellow men. I have seen very successful people otherwise but suffering in love.
3. Investing methods like mutual funds and benefits of compound effect.
4. Some basics of bodybuilding along with how our physiology works.
5. Communication skills.
6. Selling skills. Like it or not modern life is all about selling yourself and others.

https://hemantpandeyblog.com/2017/10/12/what-are-the-most-important-things-i-can-teach-my-child-including-both-skills-and-behaviors-how-can-i-ensure-this-training-sticks/