I would have realized much sooner (than the final semester) that I don’t really want to teach English, so I could have switched to straight English with an Education minor. If I’d done that, I’d probably have gone to grad school and become a certified elementary teacher by now, instead of what I do now. (oddly enough, it does use my silly English-teaching degree…but I’m paid worse than a teacher. At least most of them get health insurance and steady hours 
) Of course, I could still be miserable, who can say?
I’d have realized that guy wasn’t the one for me sooner, and my self-esteem would be better for realizing he didn’t feel that way because of orientation, not something I did wrong.
I would have told my parents that I was bored at school in fifth grade rather than in tenth. It could have saved me five underachieving years.
Barring that, I would have asked for lessons in a foreign language or two during those five years.
I would change a few things.
Firstly I spent my very late teens and very early twenties doing some hurtful, self absorbed type things. I still cringe when I think of them. I’ve made peace with those I hurt, but I would rather I had not done those things.
I would have made sure I kept in touch with friends I made along the way.
I would have made it home for more holidays when I was living away from home.
Maybe I would have thought about marriage more seriously when I was in my early thirties. It was never and I mean never on my radar screen.