Bad mood days are weather, not climate. Don’t rename yourself because of one gray afternoon.

A single bad day is a condition passing through, and the mistake is upgrading it into a description. A low Tuesday becomes the belief that you are a miserable person, which outlasts the Tuesday by months and starts collecting evidence for itself. One afternoon is not enough data for a conclusion about your nature.

Let a bad one be a bad one and resist writing the summary while you are inside it. Postpone any large verdict about your life until a day when you have slept and eaten. If the grey stretches on for weeks rather than hours, that is worth telling somebody about instead of carrying alone.