How does the excerpt show that the character john developed the theme that growing up means dealing with the circumstances you are given even if they are scary or difficult?

During the events of the story, John starts to develop a stronger personality, much more like his father. In this excerpt, John seems to have lost part of his constant fear and insecurities, feeling proud about the other driver boy on the canal despite of the situation occuring  around him.

what book are we talking about here