Our state of mind plays a major role in our day-to-day experiences as well as our physical and mental well-being. If a person has a calm and stable mind, this influences his or her attitude and behavior in relation to others. In other words, if someone remains in a peaceful and tranquil state of mind, external surroundings can cause them only a limited disturbance.
The Heart of Compassion: A Dalai Lama Reader (ed. Full Circle Publishing Company, 1997)