I would redo basically everything educationally and professionally. This feels like a terrible thing to complain about because so many people are told they'll never amount to anything and they're never given a chance to find out who they could become--but I had that stupid "gifted child" experience of being told that I could grow up to be anything I want and that college would be amazing for me, and the result was that I never got a grip on how to do anything and now I'm broke and unemployable. I'll boil it down to two items:
1. I wish I had gone to a trade school instead of college. I'm so clumsy and stupid that I would likely have failed to learn a trade anyway, but I would have had way more of a fighting chance in life if I had acquired at least one skill that anyone actually needs.
2. I wish I stayed at the corporate nightmare job that I hated. Yes, even if it killed me, which I thought it might. I was ridiculously lucky to get hired at that place when they were dangerously short-staffed, and I made more money than someone like me could ever have hoped for--but the people I worked for were kind of evil, daily life was excruciatingly stressful, MANY of my coworkers went into therapy just because of the job, and I reached the point of alcoholism because I was so nervous all the time that all I could do was drink. Then, because of a bunch of circumstances I won't get into, I was able to quit working for a little while and focus totally on professional writing, which I had always dreamed of doing, and I was immediately offered a truly amazing opportunity to work on something real, with established professionals, that could have changed everything for me. Everybody in my life congratulated me for being so brave, and filled my head with ideas about how I was fulfilling my destiny. Naturally this did not work out, and now I'm in a desperate fight for survival. If I had just stayed a few more years until the layoffs started happening, or until the company folded soon after, I could have gotten severance and unemployment. Now I'm completely fucked and it is absolutely, totally my own fault.
TL;DR I would do over anything in my life where I decided to believe in myself and take a leap of faith on achieving my dreams. I know that's kind of a messed up thing to say and there are people out there who are well served by such courage, but I'm just not one of them and I wish I had figured this out a lot sooner. I wasted all the resources I ever had trying to fulfill my potential or whatever, and now I'm constantly praying for another miserable, anonymous job to come along and save me from my mistakes.
