According to Ryan Adams (in the Whiskeytown song "I Hope It Rains at My Funeral"): "No sense in wanting my life to live over. I'll Find different ways to make the same mistakes again"
Now if you get over the depressing elements of that statement, You'll realize you shouldn't live your life in regret. Just accept the shit that you did and the shit that happened to you.
Ofcourse that leads me to the mood I've been in lately. The "What does it all mean?" one (very High Fidelity) but at least it's a question that can be answered & dealt with. As opposed to trying to imagine your life if you had a rewind button.