Well, if it is similarities that you are focusing on, you might want to think about the way in which the film presents the life of Chris McCandless in a similar fashion to the book. That is to say there are two time periods: when Chris makes it to Alaska and then his life before Alaska. The film jumps between these two linear time periods. Of course, one aspect the film does not cover is the own incidents of John Krakauer and his own "into the wild" experience that he shares with the readers of his book. I must admit, I thought that the film was quite a faithful rendition of the life of Chris McCandless as revealed to us in the book. It shows how he was able to connect with all kinds of people and also the way in which he was trying to withdraw from society, trying to attain a kind of Emersonian solitary existence just living off his own wits in the middle of nature.