In narratology and comparative mythology, the hero's journey, or the monolith, is the common template of stories that involve a hero (male or female) who goes on an adventure, is victorious in a decisive crisis, and comes home changed or transformed.
A hero ventures forth from the world of common day into a region of supernatural wonder: fabulous forces are there encountered and a decisive victory is won: the hero comes back from this mysterious adventure with the power to bestow boons or gifts of one type or another on his fellow people.
The functions of myth are mystical, cosmological, sociological, and psychological.
The first function of mythology is to invoke in the individual a sense of grateful, affirmative awe before the monstrous mystery that is existence.
The second function of mythology is the present and image of the cosmos, and image of the universe, round about, that will maintain and elicit the experience of awe, or to present an image of the cosmos that will maintain your sense of mystical awe and explain everything that you come into contact with in the universe around you.
The third function of a mythological order is the validate and maintain a certain sociological system: a shared set of rights and wrongs, proprieties or improprieties, one which your particular social order depends on for its existence.
The fourth function of myth is psychological. the myth must carry the individual through the stages of life, from birth through maturity, through old age to death. The mythology must do so in accords with the social order of the group, the cosmos as it is understood my the group, and the mystery of existence.
Myths show how to live a human lifetime under any circumstances. It is this pedagogical function of mythology that carries the individual through the various stages and crises of life.