If we were to make a list of the people we don’t like–people we find obnoxious, threatening or worthy of contempt–we would find much about ourselves that we can’t face. If we were to come up with one word about each of the troublemakers in our lives, we would find ourselves with a list of descriptions of our own rejected qualities. We project these on the outside world. The people who repel us unwittingly show us aspects of ourselves that we find unacceptable, which otherwise we can’t see. Traditional lojong teachings say it another way: other people trigger the karma we haven’t worked out. They mirror us and give us a chance to befriend all of that ancient stuff we carry around like a backpack full of granite boulders.
— Pema Chödrön, Comfortable with Uncertainty: 108 Teachings on Cultivating Fearlessness and Compassion (p. 163)