And by literally reliving your childhood I mean going back to when you first became aware of your existence, with the knowledge and abilities you have now?
I would probably try to find out why my parents divorced, and, if I could, stop them. I'd also try to become more social, because looking back on my childhood, the one thing I know I should've had back then were friends (I met my first, and only, true friend three years ago; nobody ever really talked to me beforehand). And maybe, if my parents are still together, I'd wish for a sibling... and hopefully get one before I turn 5, so that way our ages won't be so far apart (my oldest sibling is 9; we're 7 years apart) and we'd be as close as true friends (and if they were male, maybe I wouldn't hate guys so much).
What would you do?