What is some of the strangest facts about famous movies?

The Boy in the Striped Pajamas may not be mind-blowing, but I find it interesting.

To get the performances out of their young stars, the film-makers specifically cast children (Asa Butterfield, then 10, and Jack Scanlon, 8) who didn't know a whole lot about the Holocaust (the kids knew some, but not a lot, and definitely not about gas chambers).  They felt that would help the children better portray the innocence of the characters. 

To help maintain this innocence throughout shooting: 

• the film-makers filmed the scenes in order so as not to reveal information to the kids before the scenes they were working on;
• the context and import of the scenes were never explained to the kids;
• everyone connected with the film was instructed not to tell the kids anything about the Holocaust - any questions the kids had were directed to the kids' parents (Asa Butterfield in particular, who was in virtually every scene, had lots of questions - the film-makers later said that he mostly figured things out along the way).

But even the parents were asked not to tell the kids about the ending until it came time to film it.  So when the boys were finally told about the ending and taught about gas chambers, the revelation understandably left them both a bit shaken.

The day of the shoot, both boys were terrified.  Jack Scanlon (Shmuel) was near tears.  Asa Butterfield (Bruno) later said he couldn't stop thinking about how this really happened and how people had really died this way, and he kept feeling like he was going to throw up.  The boys were holding onto each other for dear life.  Everyone said that day was really, really hard.

 Fortunately the boys do not appear to have been traumatized for life by being forced into a gas chamber just after learning what one was.