On the allure of risky adventures to men, there is a quote by Tolstoy at the very beginning of Chapter 3, which was found highlighted by McCandless in a book:

"I wanted movement and not a calm course of existence...I  felt in myself a superabundance of energy which found no outlet in our quiet life."

On the bond between fathers and sons, the author Krakauer talks of his own relationship with his father in Chapter 15:

"Two decades after the fact I discovered...something not unlike affection (for him).  I came to understand that I had baffled and infuriated my father as much as he had baffled and infuriated me...his struggle to mold me in his image had been successful after all...it had simply found expression in an unintended pursuit."