Have you ever heard a joke so many times you've forgotten why it's funny? And then you hear it again and suddenly it's new. You remember why you loved it in the first place.
I can see why people adore this movie. It's just so out there...I guess I don't really have the secret admiration for killers, for people who just don't give a crap about other people. I think they are inconsiderate and stupid as hell. Though I do like the irony for mass media.