In our everyday life we can see that it is this sharpness of ego, of "I," of "me," that hurts all the time, whether it be in someone closely related or not; whether it be son, or daughter, father, mother, brother, sister, or just a friend. If anything about them hurts us, it is just this ego. If one person hurts another, it is only because of that person's ego. If ever we experience suffering in this world it is through that ego. Sometimes it is the ego of the other person, but sometimes it is our own ego also. One may compare it with a thorn which is always pricking: it hurts whoever touches it. The more egoistic person is, the more it hurts. So the teachers of mysticism know they must humiliate this ego, and to do this adopt various methods.