When someone states a fact loudly, ask one calm question: “Where’d you hear that?”

Volume is not evidence, though the two are easy to confuse in a conversation moving fast. Asking where something came from is not an attack, it is the ordinary question that should follow any claim, and most confident statements have never been asked it. Sometimes there is a solid source. Often there is a half-remembered video and a strong feeling.

Ask it calmly, with real curiosity rather than a trap in your voice. Ask it of yourself just as often, especially about the things you repeat. Anything you cannot source is worth holding more loosely.