Joseph Campbell, The Hero With a Thousand Faces

A hero goes on an adventure, is victorious in a decisive crisis, and returns to the ordinary world, changed or transformed, and shares that gift with their community. Before any of this can happen, the hero must answer the call to that adventure. The hero is reluctant at first refusing the call. A mentor appears, and helps them to cross threshold leaving the ordinary world for the new one. In real life it can be hard to recognize the call for adventure, it is almost always something that you are afraid to do, but know inside that you need to do. It appears as an obstacle. To be the hero of your story, you must answer the call, and the obstacle is the way. - Joseph Campbell, The Hero With a Thousand Faces