Anybody’s polite on a good day. Your bad days are the actual interview.

Politeness on a good day is close to automatic, which is why it carries so little information. The useful sample is what happens when you are tired, embarrassed, hungry or behind: whether your voice changes, who gets the short answer, whether the person nearest you pays for something that went wrong elsewhere. Everyone around you collects that sample without meaning to.

Choose one bad-day habit and interrupt it this week: the tone at home, the message left unanswered, the snap at whoever asked something harmless. Say out loud that you are in a foul mood instead of distributing it. Naming it is most of the repair.