What is forgiveness? Lewis Smedes, in his paradigm-changing book Forgive and Forget, stages the process of forgiveness this way.
1) You surrender the right to get even with the person who wronged you.
You will no longer engage in ways of making them pay for how they wounded you.
You give whatever justice should be exacted over to God.
You let it go.
2) You reinterpret the person who wronged you in a larger format.
You begin to see the person as God sees them (much like the forgiveness seen in "The Shack," where Mack sees people as God sees them).
This helps us avoid creating a "caricature" of the person who wounded us. "In the act of forgiving, we get a new picture of a needy, weak, complicated, fallible human being like ourselves."
We begin to see that we are "that kind of people" too, not in the details, but in the heart.
As you begin to view the person who hurt you this way, forgiveness is taking root in you.
Forgiveness will be securely planted in you when you experience stage three, as a matter of your heart.
3) You develop a gradual desire for the welfare of the person who wounded you.
At this stage you are like Jesus, who loved us even as we were his enemies and wounded him on the cross.