What is the theme in The Power of Myth by Joseph Campbell?

The underlying theme of these interviews illustrates the power that myth has to transform our lives from the mundane to the extraordinary. You don't have to be Bilbo Baggins to embark on a hero's quest. We are all on our own hero's journey the moment we are born. Campbell uses myth-based cultures and beliefs to provide a blueprint of how myth is such a powerful force in human development.