In describing the monomyth, Campbell not only identifies the many commonalities among a variety of world mythologies but also theorizes why these commonalities exist. He hypothesizes that human stories do not change because humans themselves do not change. The hero’s journey and the cosmogonic cycle, dual faces of the monomyth, come from universal human desires and fears. Campbell states:

it appears that through the wonder tales—which pretend to describe the lives of the legendary heroes, the powers of the divinities of nature, the spirits of the dead, and the totem ancestors of the group—symbolic expression is given to the unconscious desires, fears, and tensions that underlie the conscious patterns of human behavior (255-56).

Campbell uses the theories of psychoanalysis to support this point, such as Freud’s well-known Oedipus complex, which states that young children compete with one parent for the affection of the other. In both the hero’s journey and the cosmogonic cycle, Campbell identifies ways in which these tales mimic the world of the unconscious mind. Furthermore, the mythological goddess figure represents a universal mother, and the god of the universe represents the father. Creating myths helps people process their childhood neuroses, which heavily involve their parents according to psychoanalytic thought, and advance to the next stage of personal growth.