Anybody’s kind in a good mood. The real choice is being decent when you’re tired and annoyed.

Kindness on a good day costs nothing and reveals nothing. The version that means something arrives when you are tired, irritated and would rather not, because that is when it has to be chosen rather than simply felt. Nobody manages it every time, and the aim is not to.

Pick the moment in your day when you are most reliably short with people. Do one ordinary decent thing in that window, and let it be small enough that you will actually manage it.