"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.
"Start where You are: A Guide to Compassionate Living". Book by Pema Chodron, 1994.
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