The epigraph in Chapter 3 describes a book on McCandless's possession. In it was a highlighted excerpt from "Family Happiness" by Leo Tolstoy. It pretty much talked about stepping outside of one's comfort zone to seek truth. In chapter 3 Westerberg picks up a hitchhiking McCandless in Montana. Chris is talkative about, among other things, "rubber tramps". THese are people who simply wander looking for change outside their comfort zone, by car.
I chapter 6 there is a description about Ronald A. Franz, an elderly man lost his wife and his only son from a car accident .This connects with how Franz's life was touched by Chris. How Chris was to help heal this guy while feeling incomplete himself.
Chapter 11 begins with a passage highlighted by Chris from Boris Pasternak's Doctor Zhivago.Basically the passage is about finding purpose in life, "you needed to surrender to some such ultimate purpose more fully..."This is a segue that leads into Chris's past and the reasons he might have needed to find a "purpose" in life.