Past and Present

A friend and I were talking about experiences that we've been through, would we change things if we knew everything now. I'm sure everybody thinks this but would you change things? I would like to think the choices I made some how happen in a different life ( If I went left in this life, I went right in my other). I do wonder if I would be happy in either life, how my choices would be different and how I would be as a person. Would I still be in this position I am now ?