Why do people sometimes forget what they came into a room to get or do, but remember it a couple of hours later completely unprompted?


Why do people sometimes forget what they came into a room to get or do, but remember it a couple of hours later completely unprompted?

In: 295

The threshold.

The brain remembers things until the “scene” changes. Once you go to another room, area, or pass a divider, your brain thinks the thoughts you had while in the previous area are no longer necessary and doesn’t try to keep them.

You can get them back, they aren’t erased, but they just aren’t actively kept in short term memory.

In a restaurant it’s called cooler amnesia. Walk in, forget why. Turn and walk out the door, bam! That’s what it was…go back in…

This is my stupid take.

It’s when you switch from sub conscious to your conscious self.

I’ve found that if I trust my sub conscious self and just don’t think about it and let my body keep auto piloting I can get it back.

So that’s a nice mindfulness exercise.

Just remember who told you!

It’s something known as the Doorway Phenomenom or Doorway Effect and while it’s relatively well acknowledged that out does happen there’s far less agreement on why it happen.

One theory postulates that is due to how the brain catagorozes and stores memories. Rather than a single long stream of memory we believe that the brain tends to store memories episodically. Basically that means that it remembers bits and pieces of the key information of what it actually remembers and allows you to “fill in” the rest. This is one reason that eye witness testimonies can sometimes be dramatically different from what really happened and why two people can witness something but disagree on details while agreeing on major points.

As for why this happens at a doorway specifically – the theory is that your brain recognizes this doorway or entry into a new location as the boundary for something new so it essentially starts a new memory(/thought process) in the middle of the previous one and there is a moment that is very much like buffering where your brain is trying to catch up to itself knowing that whatever you were just thinking about is important it is also trying to interpret all of the new stimuli from the new location. Whether you realized it or not in the previous room your brain was looking at everything around you and choosing what it could ignore. You saw a chair and walked around it but after that the chair is basically unimportant. Your mind registered all the sights and sounds and smells, but filtered out the majority of them because they weren’t important to the task of moving into the next room. However as soon as you enter another room all of a sudden almost everything is new and needs attention. Just like in the previous room your brain will almost immediately filter most of this out as unimportant, but the immediate info dump takes a split second to filter through.

So while that may answer the “how” it happens it still leaves the question of **why** does it work that way. One theory is that it served as an evolutionary advantage to primitive humans. The idea is that in a time where actual survival was predicated on paying attention to your new surroundings (ie make sure there’s not a predator that is going to eat you in this new area) your brain is effectively saying “there may be danger here, I need to be alert, oh and also that area you just left is definitely safe so I no longer need to waste processing power thinking about what was happening there”

I agree with the threshold / doorway effect, but I see it happening to 70+ year old me as this process:

Wife says “Go get x for me from the kitchen”

I think to myself “Grrr I’ve got to get out of my recliner, walk in there, look blankly at the counter…”

And in doing that I have lost the memory of “x” completely.

Yes, it is embarrassing to have to ask her what she sent me in there after.