A dream is a state of consciousness that occurs involuntarily during the sleep of an individual. During which the mind creates stories. It arises 3-4 times a night for 15-20 minutes every 2 hours during the 8-hour sleep period.

The sleep cycle occurs in 5 stages. The first four stages do not really have a name but the fifth stage is called the REM – Rapid Eye Movement stage. During this stage the person’s eyeballs are seen to be moving under the eyelids and if awakened then he/she would remember the dream exactly. This stage makes up for about 20-25% of the sleep cycle. During the REM stage the body creates memories, retains information and increases hormones such as serotonin. 

Many psychologists believe that dreaming has a purpose and a meaning but what is it is still a mystery. Sigmund Freud, a famous psychoanalyst believed that dreams are a way for people to express guilt and desires and to conquer traumatic experiences. Whereas Carl Jung, a Swiss psychiatrist believed that dreams provide an image of the future which helps the dreamer to predict future events. 

Forgetting dreams is a very common process. Most of the dreams are forgotten right after waking up or a few minutes after. This type of dreams is called white dreams. This happens because the brain does not encode the information it creates unlike it does when we are awake.

Quite a few of the dream themes are common amongst people although most of the dreams are unique. People of the same culture, ethnicity, environment are said to have common theme dreams. Some common dream themes are falling, being chased, flying, doing something over and over again or sexual activity.

Sources: https://www.psychologytoday.com/us/basics/sleep/understanding-dreams https://blog.dreambook.app/psychology-of-dreams https://www.brescia.edu/2016/09/psychology-of-dreams/