When someone makes a cutting remark at work, when our boss dismisses our carefully prepared proposal with the wave of a hand, when our best friend reveals a confidence to a superior and puts our career at risk, how can we avoid feeling hurt and vengeful? Only if we acknowledge forthrightly that we ourselves are not above such things, that in another time and another place we might have done the same, that all of us are flawed and often act less than our best — only then can we find it in our heart to forgive.
That is why Buddhism says: Begin with yourself. Know yourself thoroughly enough to be able to say "It is all right. I can forgive myself and accept myself for who I am."
Forgiveness is not just an intellectual exercise. It is physical, and its center is the heart.
— Lewis Richmond, Work as a Spiritual Practice