In a way, the postcard from Alex to Wayne that is quoted at the outset of "Chapter One: The Alaska Interior" is the most important passage. This is for several reasons. One is that it is the source from whence the title of the book is derived. Another is that it clearly states Alex knew his "adventure" might prove fatal and be the end of his life:"If this adventure proves fatal ...." Another is that it gives a slight glance into Alex's psychological mentality and sheds a speck of light onto Krakauer's quest for the meaning of why young men are drawn to challenge nature in the wilderness.
April 27th, 1992
Greeting from Fairbanks! This is the last your shall hear from me Wayne. Arrived here 2 days ago. It was very difficult to catch rides in the Yukon Territory. But I finally got here.
Please return all mail I receive to the sender, It might be a very long time before I return South. If this adventure proves fatal and you don't ever hear from me again I want you to know you're a great man. I now walk into the wild. Alex.
This is really a matter of opinion, and I think it should be your opinion. Ask yourself which part of the book was most exciting, or most meaningful to you. I think there are many parts of this book that would create a strong emotion in most readers, but one probably mostly appeals to you.
This is going to be a very open question, and I am not sure there is any "one" answer. What I suggest you do is try and answer this question based on your own experience. When you read the book, which passages stuck out as being important from your own ideas about the book and what the author is trying to convey and what he makes of the life of Chris McCandless? If you want a hint or a suggestion, you might want to turn to chapters where the author tries to discuss such questions to see what conclusions he draws.