What’s one thing you did that you really wish you could go back and undo?

I quit high school when I turned 16 in 1966. I let people talk me out of it. If I could do it over again I would quit and head for California and find a rock band that could use a pretty good guitar picker. I'm a college grad and never made more than $10 an hour in my entire working life. A totally worthless human being but I could sure shake, rattle, and roll!