Two friends are talking about a trip they took years ago.

“It rained that day. That’s why we were late,” one says.

“There was no rain. We got lost,” the other replies.

Both are sure they remember correctly. Does that mean one of them is deliberately lying?

Not necessarily. Both may be describing what they sincerely remember, even if some details are wrong.

The brain does not replay the past like a video

We do not notice every detail of an event, and we do not retain everything we notice. Details can also change when we recall the event later.

A National Academies report explains that memory is not a permanent record protected from outside influences. Errors can arise at different stages, from observing an event to recalling it later.

Remembering is therefore different from replaying a recording. The brain pieces together stored details to reconstruct an event, and other information can become part of that reconstruction.

Something you hear later can become part of the memory

Suppose someone says after the trip, “What a rainy day that was!” Months later, you might forget hearing that comment and remember the rain as something you saw yourself.

This does not happen every time. But research suggests that information received after an event can alter our recollection. If we forget where a detail came from, we may mistake it for part of our own experience.

What about memories that feel especially vivid?

You may feel that you still remember exactly where you were and what you were doing when you first heard an important piece of news. Researchers call memories of this kind flashbulb memories.

In a study published in 2003, Jennifer Talarico and David Rubin examined the memories of 54 students. The students wrote about first hearing the news of the September 11 attacks and about an ordinary event. They were asked about those events again after different intervals.

Over time, accounts of both kinds of events became less consistent with the initial descriptions. Yet the students retained greater vividness and confidence in their memories of hearing the important news.

There is an important distinction here: the study did not establish that every detail in the first account was true. It examined how closely later accounts matched the initial ones.

The details of a memory can change while the feeling of “I remember it clearly” remains.

How much should we rely on our memories?

We depend on memory in everyday life. But when an important decision rests on a particular detail, it helps to check supporting evidence too.

  • Do you remember the exact words or their meaning? Before saying, “That is exactly what he said,” consider whether you remember the wording or just the gist of the conversation.
  • Is there a message or receipt from the time? For dates, payments and agreements, check messages, receipts or notes alongside your recollection.
  • Did you see it yourself or hear about it later? Consider whether a detail came from your own experience or from someone else’s account.
  • Leave gaps rather than filling them with guesses. There is nothing wrong with saying, “I don’t remember this part clearly.” That is more useful than inventing a detail to complete the story.

These habits cannot make memory error-free. They can help us avoid rushing to the conclusion that whatever we remember must be correct.

When two people remember the same event differently, do not immediately assume someone is lying. Look together for messages, photos or other evidence from the time.

Sources

National Academies: Identifying the Culprit — Vision and Memory

Talarico & Rubin (2003): Confidence, not consistency, characterizes flashbulb memories