only 5.9 average rating? undeserved

What a pity. I just saw this movie, it felt a little too short but I liked it in general, it is funny and doesn't exaggerate its jokes or is too vulgar like many American 'comedies'. The movie stays close enough to the novel imho, and the characters are well played. As so often, I am disappointed from the av rating imdb users gave it. F.e. "The Hangover" has an av 7.9 rating...
7 out of 10 for sure.