That agitates the ever loving fuck outta me too... When you're watching an obvious drama or horror movie with NO hints of humour in it whatsoever - and all the fuckin' cunts in the theatre are laughing as if it were a non-stop comedy. Horse-shit! What the fuck?
This is why I've gone from going to the theatre once every week, to seeing about 3-4 movies per year now. Thank fuck for DVD & Blu-Ray!