What are somethings you wanted to know before you became an adult?

I was thinking of all the things they expect us to know before we become an adult (or 25). Some I get we should know how to cook and save money and things like that. But others like getting a driver's license, buying a car or house and how to do a cover letter aren't so easily to learn and they're definitely not taught in school or college. So what are somethings you wish you had learn or things you wish the younger you knew then that you know/learned now??