[S]omething inside us, the feeling of resentment, the feeling that wants to get one's own back, must be simply killed. I do not mean that anyone can decide this moment that he will never feel it anymore. That is not how things happen. I mean that every time it bobs its head up, day after day, year after year, all our lives long, we must hit it on the head. It is hard work, but the attempt is not impossible.