A rumor travels the whole school by lunch. The facts are still tying their shoes.

Stories travel fast when they are simple, surprising, and cost nothing to repeat. The truth is usually none of those. It arrives with context and a couple of boring details, and by the time it shows up everyone has already decided. That head start is why a person can spend weeks undoing something that took one lunch period to spread.

You mostly control one link in that chain, which is you. When something juicy reaches you, ask the person how they know, and sit on it for a day. If the story is true it will still be true tomorrow.