In The Hero’s Journey, Joseph Campbell gives us a map. On this map, there is a boundary – a threshold. It’s pretty soon after the “denial of the call to adventure.” In stepping across the threshold, the
hero moves from the “ordinary world” into an extra-ordinary world.
Think of Skywalker: “I can’t go to Alderaan! I have moisture-farming to do here on Tatooine.” Then he meets Obi-Wan. Then they cross the threshold and off they go on a journey.