Mine would be really simple... no desire to change anything in my life because our mistakes and our wins are what make us what we are... but I would turn back to when I was a late pre-teen and spend a LOT more time talking with my grandparents about their life so that their experiences would be able to enrich my life more. Same with my parents, I would have spent a LOT more time with them, because you don't recognize how (usually) an integral part of your life they were until they are no longer around and you do like me, cooking a something or fixing something that takes you to a flashback of watching/helping one parents.