That's sad. Not as sad as the bursts of people tweeting with incredulity that Titanic actually happened when the movie was rereleased recently, but it's still pretty sad.
I never know if I want to laugh or cry when that happens. My stepsister was freaked out when we had watched a Titanic documentary when the movie first came out and she realized it wasn't a behind-the-scenes of the movie. I still haven't let her live that down (her kids even tease her about it now).