The tone you use with your mom when you’re tired is a better measure of you than the tone you use in interviews.

Anybody can be pleasant for forty minutes in front of a person deciding about them. The honest sample is how you sound at the end of a long day to somebody who is not going anywhere and therefore cannot punish you for it. Tiredness does not invent a new personality, it just strips away the effort that was covering the default. That is why the kitchen at ten at night tells you more than any interview.

Listen to your own tone once this week when you are worn out. If it comes out sharp, say so within the hour rather than letting it stand.