I have a dream! But I can’t remember it…
In my previous post, “Is Truth Beneficial and/or Socially Constructed?,” I mentioned as a counterexample to the pragmatist theory of truth a nightmare a person had which she did not tell anyone about and kept as a secret for the rest of her life. The nightmare was so horrible and embarrassing that every time she remembered her nightmare, she was disturbed. Her life became a nightmare of sorts because of that nightmare.
Actually this kind of scenario is very rare in real life. The fact is that we tend to forget our dreams and nightmares soon after waking up. Even before we get up from bed, most of the content of our dream has already evaporated from our memory. We remember only very few, if any, of our dreams and nightmares in the rest of our lives. The ones we remember for a while are the ones which were extremely interesting or shocking for us, or those we had the chance to tell other people about on many occasions, which kept our memory of them alive. Ask yourself how many of your dreams and nightmares you still remember. I bet very few, if any.
The interesting thing is that we forget even the most vivid of our dreams and most frightful of our nightmares in the twinkling of an eye (unless our memory of them is reinforced by telling other people about them or by intentional recalling, for example). We forget our dreams even though some of them are more vibrant than certain waking experiences which we remember for much longer time.
Psychologists and brain physiologists tell us that dreams serve a useful function for our brain. So we have to have them. But it seems we also have to forget them fast after having them. I think there is a simple evolutionary explanation of this phenomenon. If we were to remember our dreams long after we woke up, we would be disposed to confuse the memories of our dreams with the memories of our waking experiences. Suppose I have a dream in which a friend of mine does something evil to me or an enemy of mine does a big favor for me. If my brain were to retain as lively a memory of that dream as the memories of my real life experiences, I might mistakenly think the contents of my dream correspond to some real experiences of mine that occurred in the past, and my attitude towards my friend or towards my enemy would unnecessarily be affected by that mistake. Such disorientations clearly would have negative survival value and therefore would be blocked by the mechanisms of human evolution. Hence the elusiveness of our dream contents.*
A search on the Internet shows that many people have thought up the idea that our dreams’ fast vanishing from our memory has some evolutionary advantage or other. I found a blog (http://ianwallacedreams.com/who-dreams-wins/) where an idea which is in some ways similar to mine is mentioned by the “dream psychologist” Ian Wallace:
… if our dreams are so important, why do we forget them so easily? … [W]hy do we let them slip away so easily? The answer is that we naturally seem to forget our dreams because of a simple function of how the dreaming process has evolved biologically.
The evolutionary reason that we forget our dreams is so that we can quickly distinguish between our dreams and waking reality when we wake up. Otherwise we might behave like startled dogs woken from dreams of rabbit pursuit, bewildered and slightly psychotic. In our past, we needed to quickly step from the caves of our dreams into a conscious reality so we could fend off sabre toothed tigers and pursue herds of passing Megaloceros.
… Forgetting our dreams was an evolutionary adaptation when we were animals.
This theory finds the basis of an evolutionary explanation of the phenomenon of dream elusiveness in the circumstance that our cave-human ancestors often had to face the precarious reality very fast after they awoke. This may be part of the explanation, but I think it cannot fully explain why we forget our dream contents not only right after we wake up, but for the rest of our life. Why couldn’t our ancestors afford to recall what happened in their pleasant dreams, for instance, when they were safe from enemies and other dangers—say, when they were peacefully contemplating the events of the day after a nice dinner at the cave? The reason, I think, is that, if our dreams were not to be wiped out from our memories for good, we could confuse our dream experiences with our waking experiences, and endure the risks such confusion involves.
But are almost all of our dreams really wiped out from our memories for good? This may not be the case, at least for a number of dreams, because of the fact that sometimes we can tell that some of our dreams are recurrent dreams. Our realization that some of our dreams recur shows that we are able to remember their repeated occurrences in the past. If we had forgotten our dreams entirely, we wouldn’t have been able to tell that some of them recur. Hence, at least some of our dreams may not have become totally inaccessible to our consciousness. Nevertheless, the majority of them should become inaccessible enough to ensure that we won’t mistake them for waking experiences.
* Instead of quickly erasing them, our brain could have tagged our dream contents as “happened in dream,” and tagged contents of our waking experiences as “happened in reality” before sending both of them to our memory. But doing that would seem to be cost-ineffective for the brain, for there seems hardly any benefit in cluttering our long-term memory with useless material derived from the dreams.