I would not do anything over.
I have long held that all of our experiences, good and bad, help to shape us into who we are. I like who I am. To change anything would be to deny my identity; to deny the self that I have become through the years. This is not to say that I have a desire to freeze life where it is right now. I will change and morph in the future, the same as I have for the past 26 years. Life is a constant flux. Without every joy and pain, who is to say who I would be? To wish for a do-over in anything is to give into regret. Regret is a scary thing to me - a thing that would eat away at the core of my identity.
We can catch only glimmers, through introspection, of what we take away from our experiences. There are memories that I am sure are major factors in who I am and memories I have forgotten. (Are these memories then? That's another debate.) One's identity is a complex thing, difficult to summarize and difficult to ever fully know. These forgotten memories, I'm sure, have been just as large of factors in my forging as the ones I reflect upon. Again, we can never be entirely certain of how things have affected us.
So while I may edit my writings and reload a videogame save, I would never re-do anything in my life. What is the point if this is not all some enormous learning experience?