Your brain takes in a lot of information during the day. Your conscious mind is not able to process all of this information while you are awake. When you go to sleep, your dreaming mind has access to this information that was not available to you while you were awake. Your dreams might reveal new insights, desires, or help you solve a problem creatively. If you remember your dreams, you will have access to more self knowledge and might learn more about your true thoughts and feelings.
Synesius of Cyrene, writing in the fourth century CE observed, "It is an excellent idea to write down one's dreams . . . to keep, so to speak, a dream diary." When we write down our dreams, or record them on tape, we are expressing an event that typically connects a series of action-oriented images, usually visual in nature. However, because dreams occur in an altered state of consciousness, one in which the biological and chemical brain ecology differs from that during wakefulness, many people have difficulty recalling these images or recording them coherently when they awaken. (Stanley Kripner)
Dreams are notoriously difficult to recall. In fact, if a dream ends before we wake up, we will not remember it. The processes that allow us to create long-term memories largely lie dormant while we sleep, which is why most dreams are forgotten shortly after waking. For instance, an important neurotransmitter for remembering, norepinephrine, exists at very low levels during dreaming, as does electrical activity in areas key to long-term memory, such as the prefrontal cortex. (reference) As the brain awakens, it starts to turn on processes needed for long-term storage. Thus, if we wake straight out of a dream, we have a greater chance of remembering it. A 2011 study showed that people who have more theta brain-wave activity in their prefrontal cortex after waking from REM sleep have better dream recall. Theta activity indicates a slower-paced, more relaxed brain state, and greater theta activity has been linked to enhanced memory while awake.
The emotional content and logical consistency of a dream also affect how much of our dreams we remember. One study found that less coherent dreams were harder to recall than ones with strongly felt content and organized plot lines. The dreams we are likeliest to retain—nightmares and other vivid, emotional dreams—are accompanied by greater arousal of brain and body and are therefore more likely to wake us up. Certain techniques can help increase dream recall. Anything that captures our attention immediately after waking interferes with dream recall, so just as you are falling asleep, keep reminding yourself that you want to remember your dreams. Let it be your last thought as you are drifting off. Keep a notepad and pen by the bed. When you first wake up, do not jump up or turn your attention to anything. Even if you do not think you can remember a dream, take just a minute to see if there is any feeling or image you can describe. Following these simple steps may cause an entire dream to come flooding back.
See also: Booze and dreams, Dreams and brain disorders, Dreams as a source of inspiration, Essential oils, Food and dreams, Hypnagogic state, Neuroprotective agents, Sleeping brain, Sleep deprivation, Weed and dreams