Theory for not Remembering our Dreams

Are there theories, credible or otherwise, why we don’t remember our dreams for very long after we wake up? I sometimes have very vivid dreams, wake up in the morning and have completely forgotten them within an hour of waking up (if I’m lucky).

I know I could write them down as soon as I wake up and that would help me remember them, but I never remember to write them down.

I understand that we don’t hold onto memories that aren’t really needed anymore, but I sometimes want to recall a dream I had and I am completely unable to do so.

Are there any good theories why we can’t/don’t remember our dreams?

Stephen Pinker threw out the idea (as far as I know, without any serious research into it) that it’s so you don’t mix up which is reality and which is fantasy.

I tend to remember my dreams, possibly because I’ve kept a diary for 35 years and generally right them down. Thus I suspect that one has to learn to do so.

This is really two questions: #1 what mechanism prevents us from remembering? #2 what purpose does it serve?

I’ve read that the mechanism is that during sleep your brain shuts off certain chemicals which are needed to transfer your short-term memories to long-term storage. As for the purpose, it allows your brain to fire random neurons without scrambling your memories.

That’s an excellent way to put it.

Here’s my favorite theory (or “model” or whatever you want to call it):

Our consciousness is a small part of what’s going on in our brain. Underneath that, we are processing inputs, making connection, accessing memories within many different thought trains that diverge and merge and free-run at random. Our conscious module has the task of selecting from that chaos and creating a linear narrative. The threads that fail to gain some conscious reinforcement eventually evaporate without being stored in memory.

The consciousness module is good at it’s job of keeping the unconscious roil under the hood and generating the illusion of an “ego”, a single, linear mind. But sometimes it breaks down and the chaos pokes through. I believe schizophrenia and Turrets syndrome are pathological examples of this. Dreams are a more benign example. Dreams are just the normal kinds of unconscious trains of thought your brain is engaging in all the time. When you waking us, the consciousness module is coming on line, but not evenly; an ongoing thread may get some partial memory reinforcement before the filter fully kicks in.

Well, I remember reading about this one theory which stated that remembering dreams could cause the spaghetti you keep in your TV (to keep it powered) to ooze out onto the floor and flooding your house (which isn’t your house at all, but somehow totally is) with water, causing you to drown. Yet you don’t drown, but find you are able to breathe and move around freely and euphorically! But you need the glowing shoelasses because… because… well you need them, but now you just can’t seem to find them. You know they’re in the closet, but you. Just. Can’t. Seem. To. Get. There! Why can’t you get there?! Oh look, it’s your dead grandmother and your 7th grade gym teacher. You’re sure they can help find the… What was it again? Nevdrmind, you’re in Venice trying to get the damn unicycle to work.

Warning! Anecdotal input ahead…

I have memorable dreams and I have the kind where a short while after waking, I have an itching certainty that some profound insight has just slipped my grasp.

So I put a pen and pad by my bed and resolved to write down any flashes of utter brilliance immediately upon waking.

It took a while for me to actually remember to do it, because it seems the transition from [certain you’ll remember this amazing thought] to [perplexed loss] is something you never see coming - only realise in retrospect that it has happened.

Anyway, I eventually woke one day with a simple but revolutionary idea for improving traffic lights - it was going to change the world and I was going to get rich implementing it. I walked off to the bathroom with a spring in my step…

… I returned from my shower and tried to read what I had written down. Utter gibberish.
It was a stream of mostly English words and made-up compound words like ‘iprasological’ or ‘trepitative’. Utter, nonsensical wibble that didn’t even make a lick of sense.

The hypothesis I formed from that was: some dreams are hard to remember because they don’t contain any meaningful or sensible construction of ideas. There certainly had been a collection of thoughts and words that my waking brain had mashed together, but only with the temporary illusion of coherence.

I don’t remember all of them but I do remember a percentage of my dreams. I can recall some of them years after the act of dreaming. I think “sometimes” real life comes close to what I have dreamed and I get a deja vu moment.

New research points at dreams as being the result of the brain sometimes noticing the cleanup process going on while we sleep.

IIRC there were more recent reports that pointed at the reasons why humans sleep, that report that that cleanup process is vital, no sleep leads to death and it is very likely due to the accumulated waste products that build up in the spaces between brain cells.

Dreams IMHO are made in part of bits of information that the brain is trying to flush away. And some items are not being disposed perfectly and are “reviewed” under some conditions. This would explain why only in counted occasions some great ideas come from sleep, but in general the thing we usually get from dreams is just gibberish.

A related theory I have that was proposed before is that the motion picture industry pioneers stumbled into “replicating” the way dreams try to make sense of the pieces that show up in the theater of our mind: cuts, closeups, changes of view, time compression, we as passive observers, etc. All those items were familiar to humans for a long time thanks to dreams, for a long time ago even before the Lumière brothers and Georges Méliès showed up. A reason why people accepted the new medium that has elements that would not make much sense if dreams did not exist.

You say you want to remember that wonderful dream you had? You would like it if you could remember just how fantastic it feels to fly? Hehehe. But I am a cup half empty pessimist. I certainly do not want to remember any of the horribly terrible nightmares I have had.

From my personal experience I did keep a dream journal for a couple of years. You MUST keep a pad and pen next to your bed and write your dreams down IMMEDIATELY when you wake up, because, no matter how hard you try, you may not be able to intentionally remember your dreams even three minutes after your wake up. But here was the funny thing. Even after a year, if I do go back and read about some now forgotten dream from my dream journal, then I can remember the dream! For me the memory is still back in there, but until I read the reminder in the journal, the dream seems to have been stored in a vault and not available to my conscious mind.

And finally, Bup, the first response to your post, has the correct answer to the question.