Humans have a long-standing fascination with dreams. Dreams were studied in ancient cultures, such as Mesopotamia, Egypt, and Greece, for their divine properties and ability to impart wisdom. Dreams have had many meanings for many distinct cultures. For some, dreams help people remember. For others, dreams help people forget. Current dream theory states that the neocortex reviews all the information from the day and releases unnecessary information, resulting in dreams. For Freud, dreams were about wish fulfillment. He saw dreams as a collection of images and symbols from daily life that represent unconscious desires. Psychoanalysis was a means by which patients could engage in free association and speak openly about their dreams, following the many paths the images might lead.

Freud argued that the unconscious desires represented in dreams are erotic in nature. He points to infantile sexuality as the source of these desires. The wishes symbolized in dreams are hidden through a process of repression and displacement, and Freud suggests these wishes have been repressed due to their sexual nature. The brain utilizes censorship to inhibit infantile sexuality from reaching consciousness. Freud maintains that all people are affected by the sexuality of their youth and have held onto certain sexual desires from their childhood.