"Be grateful to everyone" is about making peace with the aspects of ourselves that we have rejected... If we were to make a list of people we don't like - people we find obnoxious, threatening, or worthy of contempt - we would discover much about those aspects of ourselves that we can't face... other people trigger the karma that we haven't worked out.
Pema ChodronDeep down in the human spirit, there is a reservoir of courage. It is always available, always waiting to be discovered.
Pema Chodron