A dream is something experienced or seen during sleep. There are frightening dreams (nightmares) as pursued by criminals or parting with a loved one, there is also a dream achieved encouraging such ideals or get something to be desired (good dream). Everyone has had dreams during sleep either a sweet dream or a nightmare. So, why people can have dreams during sleep? At the moment we sleep, most of our brain cells in a resting state. But there are also some nerve cells that are in working condition. Therefore, there arises a dream when we are sleeping. The dream can not be separated from the activities of our daily lives and are usually associated with the impression and our own personal experiences, or influences of the external environment such as the story of the novel and drama scenes we've ever watched via TV and Film. There is also a dream caused by stimulation of our organs such as holding urine during sleep will result in the emergence of dreams relating to Toilet (WC). Another example of the dream as people will often dream when dating her boyfriend, currently has a strong desire to go to a location, or the desire to eat something, then usually those desires can be achieved in a dream. Conversely, if we are watching a horror movie before bed, the possibility of the emergence of terrifying dreams when we are in a sleep state. Hence, a psychologist from Austria named Sigmund Freud (1856 - 1939) argues that the dream is "Achieving the top of a desire". How long do we dream? According to research scientists, the average man spends ¼ (quarter) sleep time in a dream. If you're having a dream a long time (more than 1/4 of sleep), then we will feel tired after waking up.