Everyone does dream, but not everyone remembers his or her dreams. Some people can have intense memories of a dream while others remember only a few details, and others may recall nothing at all. While circumstances of how much we remember our dreams may vary, dreams are still essential toward the development of the brain.
A dream is defined as a sequence of thoughts, images and emotions that occur in the mind while a person sleeps. Dreams occur mainly during the rapid eye movement (REM) phase of sleep, which is one of the two main phases, the other being the non-rapid eye movement (NREM) phase. REM sleep is characterized mainly by the increased eye movement associated with its name, but also involves increased brain activity, accelerated respiration, relaxation of the muscular system and more intense dreams. NREM sleep has four different stages, or levels, during which dreams may or may not occur, and will usually be less intense when they do.
Not only does everyone dream, but everyone also has several episodes of dreams every night of sleep. Generally, the ability to recall a dream is tied to whether or not you wake up after having the dream or not. In other words, if you wake during or immediately after a dream occurs, chances are you will remember it and if you sleep through it, you probably will not. Some people can remember their dreams vividly for extended periods of time, and others forget them rather quickly.
People who believe they do not dream or enter REM sleep are simply not remembering their dreams. There are psychological reasons as to why the mind would actually not allow a person to remember a particular dream. An example would be when a particular dream is so intensely real that the person who had the dream would not be able to discern whether or not it actually occurred. This type of gray area between dreams and reality could lead to harm if a person allowed him or herself to believe that their dream was reality. What if they dreamed that they could walk off of a cliff and fly? In this example, the mind is better off shutting down memories of the dream rather than allowing reality to be blurred to the point of bodily harm or even death.
