What are some hard truths to know as a man?

I’m a fairly young man but not too young. I learned a lot from other peoples mistakes and I try to learn more as I live my life. I want to know if there are things every man/young adult should know? What are some hard truths to know as a man?

Edit: I’m not looking for specifically great advice but hard truths. I understand some truths may not seem like great advice but some are reality.