Men in their 40s, what’s one piece of advice for men in their 20s?

This couldn't be more true. Don't fucking lift that two man lift at work that you can totally do it by yourself because you're young and strong and maybe you've done it a dozen times before. Just don't fucking do it. I'm fucking begging you to learn from my mistake. One time was all it took for me to have a lifetime of problems since my 30's. I know the exact moment I ruined my back. 30 years later I can remember how that pop felt. It didn't even hurt bad enough at the time to need time off work. I thought I was still just fine. Ten years later, nope. And now that I'm fifty, everything hurts. It hurts to lay down in bed. It hurts when I get up in the morning. I lifted a 1gal. bottle and was bedridden for a week. My own kids had to watch me spend ten minutes crawling up a flight of stairs to my bed; they were crying and scared that the guy who was their Superman couldn't even stand up. I promise you, it can happen and you're rolling the dice every time you do it.

Edited to add more