You have not lived today until you have done something for someone who can never repay you.

The wording appears in mid-20th-century American print sources as a maxim about daily altruism. A 1962 quotation collection printed it as an anonymous entry immediately before a different quote that was attributed to John Bunyan; later readers likely misread the layout and transferred Bunyan’s name to the preceding anonymous line. A separate later attribution to the folk figure Paul Bunyan seems to have arisen from name confusion.

The saying frames a day as meaningful only if you help someone who cannot return the favor, emphasizing generosity that is not motivated by payback or social advantage.

You have not lived a perfect day until you have done something for someone who can't repay.

You have not really lived until you have done something for someone who can never repay you.