Wait a few months before you decide who someone is. A bad week isn’t a personality.

A single encounter samples someone on one particular day, under conditions you cannot see. People are noisy, and the difference between an ordinary person having a bad week and a genuinely difficult one is invisible in a single meeting, which is why first readings go wrong in both directions. Character shows in patterns rather than instances.

Hold your assessment of new people loosely and let time supply the data. Watch what repeats instead of what was striking once. Extend the benefit of the doubt you would want extended to you on your worst week.