No, because any decision or happening in the past, has influenced and shaped my present self. I've learned from every situation and every obstacle. The past has simply past; we should analyze it, learn from it and move on. I'm a firm believer of "everything happens for a reason," so to me our past is our guide to better decision-making in the future and we should seek to dissect past experiences, because it is their dissection that leads to personal growth and it's only after their dissection that we may have closure (by seeing what steps must be taken to attain closure).
If we're not at peace or we haven't moved on from past events, we might end up wasting all our energy in thinking of all the things we could have done differently, which is unhealthy.
So, I won't change any past event, because they have molded me and because, I believe it's crucial to be at peace with it (currently working on it and it has helped me put things into perspective).