The most vivid memories of shocking events are often the least accurate ones.

Memories of dramatic, emotional public events, like where you were during a disaster or major news event, often feel unusually vivid and detailed, as if they were burned permanently into the brain. Psychologists call these flashbulb memories, and studies that ask people to recount such memories shortly after an event and then again years later find that the details people report frequently change substantially over time, even though people’s confidence in their accuracy stays extremely high.

This gap between vividness and accuracy is one of the more well-documented findings in memory research, replicated using events ranging from the Challenger space shuttle disaster to the September 11 attacks. It illustrates a broader truth about human memory: it isn’t a video recording that gets played back unchanged, but a reconstruction that gets subtly rewritten a little each time it’s recalled.