Why Misremembering Can Be a Sign Your Memory Is Working Well

Why a Small Memory Slip Might Be Good News

Not long ago I told my wife I had enjoyed chocolate chip cookies from a nearby bakery. She gently corrected me: they were oatmeal raisin. That little mistake made me wonder — was this a harmless lapse, an early sign of dementia, or something else entirely?

I'm a cognitive scientist who has studied perception and cognition for more than 30 years. With colleagues I've developed theoretical and experimental approaches to understand errors like this. Our conclusion: many memory mistakes are not simply evidence of faulty processing. Instead, they can reflect an efficient, resource-constrained system doing the best it can.

The Big Picture: Heuristics and Resource-Rationality

Beginning with the pioneering work of Daniel Kahneman and Amos Tversky, psychologists showed that people often rely on mental shortcuts, or heuristics, to make judgments quickly. For example, the availability heuristic explains why people might think there are more words beginning with the letter "k" than words with "k" in the third position — because words that begin with "k" come to mind more readily.

Heuristics are fast and useful, but they sometimes produce errors. For decades this led researchers to argue human cognition is systematically biased. Starting in the 1980s, however, a different perspective emerged: in many cases perception and cognition behave in ways that are statistically optimal given noisy inputs and limited resources.

Perception, Priors, and Predictable Errors

Consider motion perception: observers sometimes underestimate an object's speed. That looked like a failure until researchers showed the optimal solution under noisy vision is to combine sensory data with prior knowledge that most objects are stationary or move slowly. When signals are weak, the combined (optimal) estimate will understate speed — the same pattern people show.

Thus, some errors reflect the inevitable consequences of rational inference under uncertainty rather than poor perception.

Memory as a Limited Communication Channel

Our resource-rational framework treats memory like a communication channel that transmits a message from your present self to your future self. That channel has limited capacity, so it prioritizes the most important information. As a result, people often retain the gist of an experience and lose fine details.

When details are lost, the mind fills gaps with typical or frequent features — which usually works well but can sometimes mislead.

So why did I remember chocolate chip cookies instead of oatmeal raisin? I retained the gist — that I ate a cookie — but not the precise details. My memory filled in the most typical cookie attribute (chocolate chips), producing a plausible but incorrect recall.

Practical Takeaways

• Minor misremembering of everyday details is common and often reflects a memory system that prioritizes relevance over exhaustive detail.
• Errors that arise only occasionally are not the same as persistent, progressive memory loss. If you notice frequent, worsening problems that interfere with daily life, consult a clinician.
• Understanding that memory favors gist can help you design better strategies for important information: use repetition, external reminders, and salient cues to preserve details you care about.

This article originally appeared on The Conversation and was written by Robert Jacobs, University of Rochester. Funding disclosure: Robert Jacobs receives support from the National Science Foundation.