One critical event in his life was his trip in which he discovered the truth about his father and his divorce. Chris discovered that his father had an affair with his ex-wife while dating Chris's mother. At this point in his life, Chris had decided he valued truth over anything else, including love. Therefore, because his father had not proven truthful, Chris felt he could no longer love his father. He deeply resented his parents for this and said this made
"his entire childhood seem like a fiction." (p.123)
This shaped McCandless' life because he no longer had respect for his parents. He felt, more than ever, that he had to escape his parents' lifestyle and find himself and the truth. It cemented his need for truth above all.
A second critical event in Chris's life was his time with Wayne Westerberg in Carthage, South Dakota. This time in his life was significant because:
"If McCandless felt estranged from his parents and siblings, he found a surrogate family in Westerberg and his employees...He liked the community's stasis, its plebeian virtues and unassuming mien." (p. 18)
This was the first time Chris found people whom he felt he belonged with, who understood him. At this point, McCandless began to understand that people really did live this way, happily without riches, and it only solidified his resolve to do the same (although he would pursue it in a more extreme way). Without forming a family bond with these people, Chris surely would not have had the familial strength needed, someone to send postcards to so as to feel like he was needed or wanted.
A third critical event in the book can beMcCandless' abandonment of his car, his Datsun, in the desert, and the subsequent burning of all of his money. This event shows Chris's devotion to his new lifestyle, as he loved that car, but felt that
"it was his moral responsibility to flout the laws of the state." (p. 28)
He drove the car off-road in the desert, where he was not supposed to, and then refused to approach officials to get it back because he would have to answer to the law. This led Chris's life further in the direction he desired it to go; it made certain that neither money nor materialistic items would contribute to his life and happiness. This event led Chris to understand his feelings even more deeply.
"Instead of feeling distraught over this turn of events...McCandless was exhilarated: He saw the flash flood as an opportunity to shed unnecessary baggage." (p.29)
Also, this event showed Chris's apparent belief that he did not make mistakes. It solidified his belief that it was a good thing he ignored the warnings of others and instead traversed his own path.