As for the author of the book, she is trying to get an idea for her character. She was having a blockage in writing until she came across the character that she has created "Harolrd" little did she know she was creating a death for a man that was living on the same world as her. It causes this movie to be the same to other movies. Because a character is created by the author and its depressing yet mixed into a romantic comedy. Though through the entire movie we get to know the characters we also get to see other things.
This film makes it post modern because Harold realizes he is part of a story and he is going to die. In all movies you notice death is something scary and sad but in this movie they make it sorta a comedy to which causes us all to laugh while Harold mopes around trying to find a way to save his laugh. It makes us laugh without us actually realizing it. But its only because Harold seems to be just another character in someones book.