I think the fact that I'm not a straight A student would have annoyed the 16 year old me.
Also, I still don't have a career path I'm going along.
And, my relationship skills still suck.
I thought I'd have had it all much more together by now..though perhaps I set myself up for disappointment.
Other than that..nothing much. I peaked at 6-6"1..which sucks. All the guys in my family are like 6'2+..so I'm the runt of my generation. How sad.