How and Why We Forget

Forms of forgetting what we intended to do.

Posted Feb 24, 2021 | Reviewed by Abigail Fagan

There are clear, practical benefits to forgetting, especially with outdated information—where you parked your car yesterday, an old password you no longer use, the PIN code you replaced, the details of a former long-term relationship. However, the focus here is on what we truly want to remember to do.

We commonly forget many small actions in our daily lives: adding an attachment to an email, returning phone calls, taking food out of the freezer, watering plants, getting printouts from the printer, charging our phones, buying what we wanted at the grocery store, turning off the oven, taking our cup of coffee with us when we leave the kitchen.   

How might we characterize this forgetting and explain it?  

1. Forgetting Forgetting

We can forget that we forgot to do something. There are unending examples of this from my own life, but I’ll limit myself to three. I wanted to cancel my subscription to an online newsletter, but I forgot. I did this several times, forgetting that I had forgotten to cancel it—until the newsletter eventually renewed for a year. The very outcome I wanted to avoid.

I water my plants twice a week (Wednesdays and Saturdays) but sometimes forget to water on Wednesday until it’s time to water them on Saturday. This happens frequently.

A final example. After I left my winter hat in the car, I went out to get it, so I could put it away in my closet. On the way to the car, something distracted me and I forgot the hat. I then forgot that I had forgotten it. I did this two more times and only remembered the next day when I needed to wear the hat again.

When we want to do something, we represent the action in short-term memory, which lasts up to 30 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 go longer than 30 seconds without completing the action or without rehearsing it, this initial representation will disappear from short-term memory. It will also go away if something new enters our consciousness, bumping it out of short-term memory.  

 Andrea Piacquadio/Pexels
Source: Andrea Piacquadio/Pexels

At this point, we may be left with nothing or we may have an older representation of the desired action in our long-term memory, possibly with a tag attached indicating that it has been recently activated. The represented action will then remain in our long-term memory—hidden from us—until an effective cue retrieves it.   

With the online newsletter, it was only when I saw the charge on my credit card that I remembered I forgot. With the plants, I have a direct retrieval cue. Seeing the plants as I water them on Saturday retrieves the memory of having forgotten to water them three days earlier. With the hat, my immediate need the next day maintained the represented action in short-term memory long enough for me to grab my hat from the car.

Our daily remembering is heavily dependent on worldly context. Once we’re out of the immediate context for the action, we lose the initial retrieval cues and we're dependent on short-term memory—an effect that is especially apparent when we change rooms. The desired action soon leaves short-term memory, unless it’s actively maintained through rehearsal. One effective retrieval cue later is the direct consequence of the forgetting—in my examples, the unwanted renewal of a subscription, plants with dry soil, and a head in need of a hat.  

To reduce forgetting forgetting, the desired action must be our primary focus, and that focus must be maintained through repetition and avoiding distraction.  

2. Forgetting Remembering

We can forget that we remembered to do something. This happens to me a lot—with actions large and small. Before cold weather sets in, I disconnect my garden hose and bring it into my garage. Then I forget that I disconnected the hose and go out a few days later to disconnect it, only to find that the hose has been safely put away.  

Nicolas Compte Unsplash
Source: Nicolas Compte Unsplash

This type of forgetting occurs when the desire to do the act is more easily retrieved than actually doing the act. In this case, the desire is not wanting my water pipes to rupture—or my hose to be ruined.1 Moreover, I have done this for years, and the context for each unscrewing and putting away of the hose is the same from year to year. It’s always in early November and always in the same location.   

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

To remember each repeated action, it helps to say something unusual to ourselves or simply tell ourselves clearly that we did it. This self-talk provides a distinctive retrieval tag, which then increases the chances of remembering. We retrieve the unusual reminder or the direct statement and remember that we carried out the action. Self-talk also enforces attention. And it is often the lack of attention that leads to forgetting that we completed a task.   

In addition, reminding ourselves two minutes after completing the action also makes the action more retrievable. Because short-term memories last about half a minute, waiting two minutes for a reminder increases the chances of easily retrieving the act from long-term memory.  

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

3. 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 two.)  

With this type of forgetting, the action is rehearsed and it’s important enough to maintain its primacy over potential distractions. We can increase this desirable pattern 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 action.  

4. Remembering Remembering 

We can remember that we remembered.

 Joel Mott/Unsplash
Source: Joel Mott/Unsplash

When that happens, we should pause and acknowledge our successful remembering – so we can maintain a balanced assessment of our memory system. Distinct examples of forgetting are more newsworthy to us than examples of remembering, and that’s understandable, but every so often we should acknowledge our remembering. In fact, one reason forgetting is so newsworthy is that it's the exception against a backdrop of appropriate remembering throughout the day. Noting our successful rememberings can nourish our memory esteem.

Final Observations

Much of our daily forgetting is due to insufficient attention and then failing to retrieve our intended action. As encoding and storage systems, we are remarkable—taking in and representing information from the world with no discernible limit. Our retrieval system, however, is limited. It is retrieval we need to pay attention to.


Note 1. The water actually shuts off a couple of feet below the outside spigot, so water that collects between the hose and the inside shutoff can freeze and expand, creating a hole in the metal pipe.