Disclaimer: There are spoilers! So go read the book first, and then come back and read my blog :)
In the book Charlie has a unique voice that he expresses through letters to the reader. We learn from his writing that he often feels isolated even from his close knit friend group, but in the movie he seems "cooler" and more connected to his friends. In the book, his character seems withdrawn and scared of most social interactions, afraid of rejection. The simple way which Charlie narrates his own story and his naivety of the world make him an easy character to love. In the movie, Charlie's personality is lost. First of all because the narrative in the movie is not explained through Charlie's letters, but by the viewer getting to see him and his friends interact without any background information from Charlie's thoughts. This decreases the amount of understanding the viewer has into the situation.
For example, the trail of hints that lead to Charlie's meltdown of Patrick's touch on his leg, his failed relationship with Mary Elizabeth, and finally kissing Sam seem to be harmless to the Charlie portrayed in the movie until his meltdown. But in the book there is this uneasiness that Charlie writes about in his letters. He foreshadows his meltdown by not being able to recall moments in his past and not being able to address his own feelings. The reader can easily piece together what happened to him with his Aunt Helen. On the other hand, I had to explain the ending in the movie where there is a montage of scenes that Charlie is at his Aunt Helen's house to the friend that I watched the movie with. The book conveys how broken our lives can be, and yet we can still heal and make new friends that will carry us through the hard times. The movie addresses some of the other big issues in Charlie's life, but misses the abortion of his sister and his own molestation.
The casting of this movie was critical to it being a success. My favorite roles were played by Ezra Miller as Patrick and Mae Whitman as Mary Elizabeth. And of course Emma Watson. But I picked the first two, because as I was reading the book I struggled to imagine a character like Patrick: that believes in such opposite ideas such as loving to go to high school football games, but hating any other type of social norms. I think they cast perfectly for this part. He was engaging and surprising the whole way through. The other odd character for me was Mary Elizabeth. She is on the fringes of the friend group, and when Charlie can’t have Sam he uses Mary Elizabeth to get by. Mae Whitman did a wonderful job of helping me to feel sorry for her, whereas in the book I felt more apathetic towards her character.
There are many elements in the book that are crucial to Charlie’s friendships. Most of the experiences that they share are more than two dimensional. The movie wonderfully captured the song “Asleep”, The Rocky Horror Picture Show, and getting high for the first time. But the best summation of the book in one scene is with the truck speeding over the bridge. Chbosky wonderfully captured the image and feeling of being infinite. The cinematography was done so well here and all throughout the movie that it really feels like the viewer is experiencing life right along with the characters.
In the case of The Perks of Being a Wallflower I recommend reading the book AND seeing the movie (However, I always suggest reading the book first, because if you know the plot line from a movie it is much less motivating to finish the book). Normally, I don't like the movie as much as the book because of the lack of complexity a movie can offer you. Maybe its because Stephen Chbosky directed and wrote the screenplay for his own book, but I think this movie is almost a perfect pairing to the book. It was very well done and stayed fairly true to the book. And no matter how you look at it this is a beautiful coming of age story.