What keeps us from forgiving the people who hurt us is that we have not yet healed the wounds they inflicted. Forgiveness is the gift at the end of the healing process. We find it waiting for us when we reach a point where we stop expecting "them" to pay for what they did or make it up to us in some way. Yet, forgiveness is moving on. It is recognizing that we have better things to do with our life and then doing them.
To learn to meet our needs without continuous violence against one another and our only world would require an immense intellectual and practical effort, requiring the help of every human being perhaps to the end of human time. This would be work worthy of the name "human." It would be fascinating and lovely.