I really enjoyed the beginning, and the end, as I could relate better, as the girl was my age, and it was really funny. So even though when she was suddenly 30, it was funny too, I didn't really enjoy it as much. I would have loved it if they made a movie about the girl at the start of the movie, and she didn't grow up... but that would be a totally different concept.
It is sad how she considers her best friend a geek, so shes totally mean to him in front of all the popular people, but after her aging of 17 years, she misses him, and realizes what a bitch she really was to him.
I love the thriller scene - its classic!!