Chapter 1: what is fosters overall point about journeys or trips in literature?

I think Foster is saying that the student must be able to identify certain archetypes of literature in a given story. So, for example, when he uses the story of Kip buying the bread and seeing his dream girl swept up by the popular rich boy, Kip decides to join the Marines. What we are really looking looking at in this instance is the hero's quest, little different from say King Arthur. Journeys and trips in literature take place in many different situations, yet they follow a particular shared context.