All of our experiences are based on others, basically. As long as we have a sense of practice, some realization that we are treading on the path, every one of those little details that are seemingly obstacles to us becomes an essential part of the path. Without them we cannot attain anything at all–we have no feedback, we have nothing to work with, absolutely nothing to work with. So all the things taking place around our world, all the irritations and all the problems are crucial. Without others we cannot attain enlightenment–in fact, we cannot even tread on the path.
From “Be Grateful to Everyone,” in Training the Mind and Cultivating Loving-Kindness, page 48.