The five dollars you gave a kid for lunch in eighth grade might be the thing he tells his own kids about.

Small help lands with a weight the helper never feels. What was loose change to you may have arrived on a day someone had no other option, and that is the version that gets remembered and retold. The mismatch between the cost and the meaning is the whole point of it.

Stop waiting until you can do something significant. Cover the small thing when you notice it, quietly and without making a moment of it. You will have forgotten it by the weekend and somebody else might not.