Every night without fail our eyes become heavy and our minds tired, and dreaming we drag ourselves to bed and normally fall asleep quickly and peacefully to the land of dreams to which we go. Why this though? Why do we sleep every night? Why do we wake up with the dream fresh in our heads? How important is this basic human routine to our survival? What happens when it is disturbed? Sleep is extremely important for all mammals, but especially for humans. Without sleep we are unable to function properly and to our full capabilities. When we sleep we grow and for us it is an opportunity to dream which has many benefits. Sleep is also a way to relieve stress. Sleep is a truly unique process, performed only by creatures with highly evolved brains. Sleep is a brain process performed by the brain for the brain (1). This basically means that everything that happens during sleep is a result of the brain, and the reason it happens is because the brain needs it. Sleep is so unique that it is impossible to mentally pretend to be asleep (1). Even if we seem completely turned off when we sleep, this is not the case. The human brain is extremely active during all stages of sleep. This has been proven countless times by monitoring the electrical activity of a sleeping person. Until the 19th century, little was known about sleep, although many great scholars and philosophers from various countries had wondered about sleep and even attempted to study sleep over the centuries. they were unsuccessful because they simply didn't have the proper technology to understand the major role the brain plays in sleep. Some had even hypothesized that the brain was a part of sleep, but they simply had no way to rest… middle of paper… the amount of time we spend in REM sleep, and NREM will increase after physical exertion (2) . REM sleep is extremely important because it is during REM sleep that most dreams occur and it is also when dreams are most vivid compared to the few dreams that occur in NREM sleep (2). During REM sleep the brain is so active that it seems as if a person is awake, especially the area that corresponds to images and emotions. During REM sleep the body becomes very still, this is known as REM sleep paralysis and is more akin to physically preventing us from realizing our dreams, a potentially dangerous activity. When this doesn't happen, people become violent and thrash or jump out of bed and may attack the people they sleep with, this is a condition called REM behavior disorder. At the opposite end of REM behavior disorder is an equally frightening experience.