Treats the driver like a dick

At the beginning of the film the driver tries to tell Doug a little story and Doug doesn't laugh or respond in any way. Really? You can't just smile and nod? Why treat someone like that? Okay, the driver's story was a total non-anecdote, but still - I don't get it how comedians can be so snobby about humour. Like if it doesn't make them laugh they'll just act like you're a *beep* piece of trash.