Do we ever truly overcome our childhood?

While answering another question, I made a reference to a very unhappy period in my childhood. I am now a happy, healthy adult with a much improved relationship with all of the members of my family, but all it took was thinking about that time in my life to bring a wave of resentment and ire. Do we ever truly overcome our past? Do we just bury it and manage to avoid the topic? Am I just a grudge holder or is everyone this way?