There are three distinct forms of forgetting.

Our most intractable forgetting can be prevented with self-talk and by sharpening the focus of our attention.

Retrieving a memory depends on refreshing the context in which we first encoded what we want to remember.

Forgetting is a necessary condition of human existence. It allows us to set aside the inconsequential, so we can recall what’s important. Good memory depends on forgetting the irrelevant. Forgetting also helps restore our vitality after disappointing or painful events, encouraging us to recover from unpleasantness more quickly. Without such forgetting, we would remember our emotional pain all too well. And forgetting provides clear, practical benefits, particularly with outdated information—where we parked our car yesterday, the pin code we replaced, the details of a former long-term relationship.

But there are also clear disadvantages to forgetting, especially with things we need to do. Such forgetting is inconvenient, frustrating, and potentially serious.

What are the different forms of forgetting and how can we avoid them?

Forgetting Remembering

We can forget that we remembered to do something. These are typically small matters, but they add up inconveniently—for example, spending time searching for our favorite sunglasses, only to discover that we already slipped them into our pocket.

This forgetting occurs when the goal for doing the act is more prominent and easily retrieved than actually doing the act.

Before cold weather sets in, I disconnect my garden hose and bring it into my garage. Often, I forget doing that and go out a few days later to disconnect the hose, only to find it safely put away. The important goal is not letting my water pipes rupture or my hose become ruined. I have done this for years, and the context is the same from year to year—always early November and always the spigot near my garden.

With repeated actions that don’t have a distinctive feature for each repetition, we often forget we remembered, as with locking a door or unplugging the iron or taking food out of the freezer.

To remember each repeated action, it helps to say something unusual to ourselves when we carry out that action or simply tell ourselves clearly that we did it. This self-talk provides a distinctive retrieval tag, which then increases the chances of remembering. Recalling the unusual reminder or the direct statement tells us that we already did what we wanted to. The self-talk also enforces attention.

In addition, reminding ourselves two minutes after completing the action also makes the action more retrievable.

The underlying reason we forget remembering is that we only need to remember the action until we actually do it. After that, memory for that action has little value.

Forgetting Forgetting

We can forget that we forgot to do something. Let’s say we want to cancel an annual subscription to a streaming service, but we forget, and forget again—until the service automatically renews for a year: the very outcome we wanted to avoid.

Another example from my own recent life is forgetting my thick wool stocking cap in the car, getting distracted while going back to the car to retrieve it, and forgetting the cap entirely. I forgot that I had forgotten it. By the time frigid weather returned and I needed the wool cap, it took me a while to figure out where it was.

When we want to do something, we represent the action in short-term memory, which lasts no more than thirty seconds. We can prolong this short-term representation by consciously repeating what we need to do (a mental process known as rehearsal). However, if we wait longer than thirty seconds without completing the action or without rehearsing it, this initial representation will disappear from short-term memory.

The compounding problem is that short-term memory doesn’t hold much, so when something new enters our consciousness, what we wanted to remember gets bumped out. Given the complexity of our lives, even a few seconds allows other thoughts to intervene. (What will I make for dinner? What was that funny line from the movie last night?)

Although the original estimate of short-term capacity was seven pieces of information, later research showed it is no more than four, at best.

This can be the most costly type of forgetting because the only effective retrieval cue is often the unpleasant consequence of the forgetting. With the streaming service, it’s only when we see the charge on our credit card that we remember we forgot.

To curtail forgetting forgetting, the desired action must be our primary focus, with this focus maintained through conscious rehearsal and avoiding distractions, until the action is completed. Another solution is to externalize memory by writing a reminder or texting ourself.

Remembering Forgetting

We can remember that we forgot to do something. This is generally considered a successful outcome. Suppose I need to put a letter in the mailbox, but I leave it on my desk. I then remember to put the letter out. This makes me feel good (unless I remembered to put the letter out earlier, and then I’m back in category one.)

This type of forgetting can be potentially serious. Suppose we’re leaving for an afternoon appointment and then rush back into the house to turn off the burner under a pot of soup that we forgot about.

We can reduce this forgetting by taking a more single-minded approach to our tasks. Attention is always divided, but with conscious effort, we can allocate enough attention to follow through and complete the desired action.

We can also be aware of context-dependent memory. That is, we remember information better when we are in the same location where we originally encoded that information. Students recall more on exams if they study in the classroom where they will be tested. This also accounts for going into a room and then forgetting the reason we went in there, and then remembering later when we return to the place where we first thought of it.

An extreme example of context-dependent memory is found in research by Duncan Godden and Alan Baddeley from more than fifty years ago. Experimental participants learned lists of words either on dry land or underwater and then later recalled these lists either on dry land or water. What made this experiment possible was that Godden and Baddeley recruited their participants from a scuba diving club at their university and then conducted the underwater portion of the research in open water nearby. The environment itself didn’t matter (dry land or under water). What mattered was being in the same environment for both learning and recalling. Lists learned on dry land were best recalled on dry land. Lists learned underwater were best recalled underwater.

The same pattern applies to our physiological state. What we encode in one physiological state is more easily recalled in that same state, an effect known as state-dependent memory. Consider the state of intoxication. Years ago at a friend’s party, I drank a couple of beers and then decided I didn’t want my car keys jingling in my coat pocket, so I hid them in a safe place—under a decorative duck decoy in my friend’s living room. Some time later, after the effects of the beer had worn off, I searched for my car keys but couldn’t remember where they were. So I stayed at the party, socialized, and drank another beer. It was only after drinking that beer that I remembered placing my keys under the duck decoy, which I then found, slipped into my front jacket pocket, and waited until sobriety returned. I needed to recreate the same physiological state in which I hid the keys in the first place.

If we have a vague feeling we’ve forgotten something, it helps to return to the places or the states and moods we were in earlier.

Atkinson, R.C., & Shiffrin, R.M. (1971). The control of short-term memory. Scientific American, 225(2), 82-91.

Cowan, N. (2000). The magical number 4 in short-term memory: A reconsideration of mental storage capacity. Behavioral and Brain Sciences, 24, 87-185.

Godden, D.R., & Baddeley, A.D. (1975). Context-dependent memory in two natural environments: On land and underwater. British Journal of Psychology, 66(3), 325-331.

Wixted, J.T. (2024). Atkinson and Shiffrin’s (1968) influential model overshadowed their contemporary theory of human memory. Journal of Memory and Language. Volume 136.

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