People over 50, what’s one life lesson you wish every 20-year-old could learn early?

Not over 50, but life has kicked my ass enough to know at least one thing. Don't go into tech, finance, etc; learn a trade; something that will always be needed like plumbing, electrical work, engineering if you really want to go to college, and is protected by a Union. I have worked in the finance sector for 15 years, and it was the biggest mistake of my life.

I have no practically valuable skills if everything goes to hell, aside from being an effective analyst who is big-picture oriented, and that honestly scares the shit out of me.