Of course this question is going to receive a range of different responses, and I think it is testament to the incredible re-telling of the story of Chris McCandless in this novel that it is able to evoke so many different responses. My own feelings about the story of Chris McCandless are ones of sadness at the tragedy and the waste of his life. I feel very attracted to his personality and the way that he lived what he believed so defiantly, even up until his death, and I must admit that I admire the way he met his death as described in the last chapter of this account before the epilogue:
He is smiling in this picture, and there is no mistaking the look in his eyes: Chris McCandless was at peace, serene as a monk gone to God.
However, apart from the enlightenment that Chris himself received, I find it tragic that his death was so unnecessary and completely avoidable. I also think it was such a waste of a young life that could have done so much to impact the world. The force of his personality is obvious. The lesson that I take from this novel therefore is never to let your own personal ideology or system of beliefs lead you into such dangerous situations without taking measures to ensure your safety. There is a sense in which the arrogance of Chris borders on stupidity, because his life could so easily have been saved.
Christopher McCandless's story is perhaps on of the great episodes of tragic heroism of our generation. The lesson living within his legacy is difficult to articulate - He was at once a great prophet of the ills our society perpetuates, brilliant young intellectual and tallented writer, and at the same time a naieve young wayward soul. Of the many angles taken to debate McCandless's validity as a free spirit versus an irrational young man, I have always felt more drawn to his passion for a life less ordinary. Some would argue that McCandless was "insane" for risking his life in so many ways, ultimately paying the gravest price for adventure. I would argue that he had to live the way he chose in order to cultivate such a passion - that passion lives on far beyond his final resting place, and is in fact immortalized in a way by Krakauer and Penn - but I also believe that the lesson in his story comes from a life lived on extreme margins so that we can know his passion without having to repeat his risks.
I think one of the big ideas that can be learned by Chris' story is that it is fun to challenge yourself, but you need to be prepared. Although he points out that if success is guarenteed then it is not a challenge, you need to ensure that there are safety measures in place.