Kindness compounds like interest. A little every day, and years later people can’t remember a version of you without it.

Small repeated decency does not look like much on any given day, which is precisely why people underrate it. Keep it up for a few years and it stops being something you do and becomes what you are known for, and by then it runs on its own because people expect it and answer in kind. Repetition is the mechanism, not scale.

Pick one small thing and do it daily rather than doing a large thing now and then. Reply, hold the door, ask the second question. None of that impresses anyone today, and it is exactly what accumulates.