Depends on how you frame the question, also depends on how you define the schooling period.

Would one keep the knowledge? Would it be going back in time and having the same classmates, living the same experiences? I’d go back just to improve or strengthen my friendships, also I’d use the spare time to learn new things as opposed to those I used to be interested in.

I’d really really would backtrack my tertiary studies and get into my current field a lot earlier. So much wasted time…