If person like Sarah haven't not influenced yours life, than this movie can be to short to make reasonable impact on you. On other side, if yours life was strongly influenced by person like Sarah, then this movie could be a little bit to harsh. Before I met such a person I was unable to imagine that this kind of people could possible exist – it just does not make any sense. It was harsh to see this movie, but it is very good to be reminded in clear way that those people exist.