"Who hurt you and why? At this point, it does not matter anymore."
I think that those things play a role in shaping the way that we view the world but the problem manifests when we dwell on them. If I go off thinking about some of the more fucked up things that I have gone through, I find myself stiring up fresh anger over things that happened 15 or 20 years ago and that isn't healthy. Finding that balance is pretty hard though and I can't say that I have been able to do it.
Past experiences taught me a lot of things in life. I try not to dwell on them but then it's understandable that I don't want to make the same mistakes or get hurt. Yeah, finding balance is pretty hard.