The first explanation that pops into your head just won the race. That doesn’t mean it won the argument.

Speed is the only thing a first explanation proves. It arrived quickly because it is familiar to you, not because it fits the facts, and familiarity is a poor guide when you are trying to understand why someone did something. Once it lands, everything after it gets read as confirmation.

When something surprises you, force a second explanation before you act on the first. Make it one that assumes something reasonable about the other person. You do not have to believe it, since holding two candidates at once is enough to stop the first from deciding for you.