...He had few illusions, for here are some of the things that life had taught him: "Men hate those whom they have injured; men love those whom they have benefited; men naturally avoid their benefactors; men are universally actuated by self-interest; gratitude is a lovely sense of expected benefits; promises are never forgotten by those to whom they are made, usually by those who make them.
W. Somerset Maugham, Collected Short Stories: Volume 4
human-nature, illusions