Everyone in this world can be a kind of teacher, but not a real teacher, for a real teacher is the one who always teaches himself; and the more he teaches himself, the more he realizes that there is so much to be learnt that a whole lifetime would not be enough. And the more one learns the more one overlooks the evil in others. It does not mean that the evil is greater or less in others, it only means that one has realized that the enemy which one saw in others is really in oneself. The worst enemy one was faced with in outer life one finds to be in one's own heart. It makes one feel humiliated, but it teaches the true lesson: of finding in oneself the same element which one wished to resist in another.