I'm not sure I'm afraid. The best understanding I have is that even though we may not remember our dreams we still do have them (i.e. if you were woken in REM s

I'm not sure I'm afraid. The best understanding I have is that even though we may not remember our dreams we still do have them (i.e. if you were woken in REM sleep you would likely recall a dream). We remember dreams using the neurotransmitter Acetylcholine. This is responsible for working memory. In the same way that it is difficult to recall a series of random numbers, a dream can quickly slip from memory because of the short term nature of the memory generated by this neurotransmitter. (In my view this supports the view that we act in obviously maladaptive ways dreams in order to highlight this behaviour. If our long term memory was storing these dreams automatically (I think you analyse a dream you do store it in long term memory, but in an intellectual way), we would be reinforcing our maladaptive patterns. By storing the dream in working memory, the brain can highlight the behaviour without reinforcing it.