You have not lived today until you have done something for someone who can never repay you. (John Bunyan, 17th century English writer)
Bunyan forces us to think carefully about how we live our lives. He argues that doing something—no matter how noble—with the expectation of being repaid is living selfishly. We haven’t really lived, he seems to say, until we learn to serve others without any prospect of being rewarded or even recognized.