If you said memoir is a form of fiction, you would be half right. It is “based on a true story,” as Hollywood says. But even most memoir writers who plan to stick with the gospel truth have to admit that they’ve partly fictionalized.

Why can I say this with certainty? Because research shows that the likelihood of remembering things without notes is low, and most memoirists rely heavily on memories—this in spite of admirable exceptions.

To grasp the full importance of notes, consider the work done by Ulric Neisser. He found that people get as much as two thirds of the facts wrong when recalling vivid memories—so-called “flashbulb” memories.

Neisser asked students to take notes the day after the Challenger shuttle explosion. They wrote down what they were doing, where they were, what they saw on TV, and so on, at the time of the disaster. Three years later, he asked them to take notes again using memories of the event. When Neisser compared the two versions, over 90 percent of students’ two sets of notes differed. Amazingly, half of the three-year-old recollections were inaccurate on two thirds of the details.

Alternately chastening and chilling. It’s a reminder that you have to write down observations in real time if you want to get details—and even the big picture—right. Notes about life, about what you’ve experienced, and about what you’ve witnessed. Without them, you can’t accurately cash in on the facts of the past.

That we remember so poorly is in keeping with the work of Daniel Schacter of Harvard. In The Seven Sins of Memory, he notes seven ways our memories go awry, from absent-mindedness and blocking to misattribution and bias. Wikipedia has a good summary of Schacter’s work.

If you rank conveying “higher truths” about life as most critical in your writing, you may not care about the facts. Sticking with dead accuracy may even obscure the loftiest truths. How you deal with fictions from your memory depends on your goals. Are you writing to convey truths that transcend facts? Or are you writing to convey facts that reveal higher truths?

Doing both seems like a good goal for nonfiction authors. Glossing over things has a lot of appeal if it helps you write a page-turner. After all, the story line of most of our lives wouldn’t excite most people much—or even make sense—without embellishment and editing. But if you’re a stickler for insisting on both the higher and less truths, facts like verbatim quotes, remember Neisser’s students. Take notes.

[Revised January 2020. Originally published June 29, 2015]