The correct answer to this open question is the following.
“If we remembered everything, we should on most occasions be as ill off as if we remembered nothing.” William James.
What Willia James tried to share with this quote was that people have to forget and live. That it is not a good thing to carry the burdens of life, generating resentments all your life. Whatever happened one year ago or ten years ago, it's in the past. To be happy you have to free of those burdens that come from time to time and produce bad feelings, just by reminding you what happened or who made what to who.
So for me is a good quote to remind ourselves to forgive and forget, and keep on living a happy life without resentments.