I've just finished this book, so I think that I should express my first and immediate opinion, later on I think I will make a deeper analysis. 
 The book basically left me with a smile upon my face, it made me want to listen to the songs that make me feel "infinit", to embrace those moments of quietness, stability and friendship. 
 I got to say that I couldn't get related to most of the story because my life is quite different, it felt distant to me. but still the way people interact in a more conceptual way is clearly universal or at least I felt it very close to the way I see myself and others in the day to day relationship. 
 I love the writting style, that it was a letter, it helps you to get involved in charlie's story; in Charile's feelings, because how many times haven't we felt dizzy with our problems in an unknown way?? Or felt mixture of feelings towards the people we love the most and like the most? 
 I really loved this book by the fact that it took me only today to read it, because I just wanted to know more and to understand more. And because it made me realized how much i appreciate the people who listens like Charlie does. still i think i'm obliged to add that this same passiveness of charlie got on my nerves! 
 At difficult situations Charlie only became an spectator, who analyzed people but never really showed any judgment of his own, the situation of her sister for example, it was meanningless, which in real life isn't. At times Charlie felt surreal, as only a vehicle to see a specific scenario and not as a story himself. 
 Just to add something else: I really liked Sam's final speech it made me nodd a lot!