Personally, I wouldn't go either way.
Sure, I've made mistakes in my past, but going back to fix them would change so much for me now. I don't think I could handle that. So I agree with what Slayr said above.
As for the future, I will definitely say no. I mean, what if you found out something terrible, and when you went back to the present it was all you could think about? I would be scared, honestly.