What Should We Remember and Forget?

While I am reading Beloved, I am very struck by the dilemma of memory. It seems to me that Sethe wants to forget her times at Sweet Home, which is perfectly understandable, but she also wants to make sure her family doesn't live the same life she did. So, I wonder what the balance is between remembering and forgetting. Should one remember as much as they can so that they can provide that much information to save people from their same fate? Or should you forget enough so that only enough remains for a general word of caution?