Just a hypothetical question for fun (as opposed to regret)...
For me, I would have studied hard to become a lecturer of history (or another subject I like) because I know that the combination of researching an area I'm enthusiastic about and passing on my knowledge to others is something that would have made me leap out of bed in the mornings. I actually ended up as a marketing writer, which is fine, but I'm still looking for my calling even at 33.
I would also have made an effort to seek out more intuitive types to be friends with because, while I love the ones I have, I always felt like a loner among them when I was young. I think I would have much closer childhood friends now if I did. I made a lot of my intuitive friends at University.
How about you all?
Edit: If you think the concept would be too abstract for a child and you are struggling with the idea, imagine slightly older.