Which is more important to Alan: what actually happened; how he perceives what happened or how he grew/changed from his trip to California?

Alan initially desires a relationship with his father.... a chance to be a son, to know his Dad, and to establish a relationship. Over the course of the novel, Alan learns the hard facts about his dad.... Alan changes and transforms through his attempts to build this relationship, and in turn, comes to the realization that his father in unable to so the same. In essence, the changes Alan undergoes become the most important part of his trip to California.