Dreams are successions of images, ideas, emotions, and sensations that occur involuntarily in the mind during certain stages of sleep. The content and purpose of dreams are not definitively understood, though they have been a topic of speculation and interest throughout recorded history. The scientific study of dreams is called oneirology. Scientists believe that everyone dreams, but people tend to forget them when they naturally pass out of sleep in the traditional sleep cycle. A person who is awakened duringREM sleep is much more likely to remember the dream.
Dreams mainly occur in the rapid-eye movement (REM) stage of sleep—when brain activity is high. REM sleep is revealed by continuous movements of the eyes. At times, dreams may occur during other stages of sleep. However, these dreams tend to be much less vivid or memorable. Dreams can last for a few seconds, or as long as twenty minutes.
Dreams are a connection to the human subconscious. They can range from normal and ordinary to overly surreal and bizarre. Dreams can often at times make a creativethought occur to the person or give a sense of inspiration. Dream imagery is often absurd and unrealistic, and the events in dreams are generally outside the control of the dreamer, with the exception of lucid dreaming. Dreamers are usually not self-aware in their dreams; thus the dreams may seem very real to them while asleep. Dreams can vary from frightening, exciting, magical, melancholic to adventurous.