4 The Shining -- The Kid Didn't Know It Was a Horror Movie
Stanley Kubrick's hallucinogenic mindfuck bonanza The Shining stars Jack Nicholson as a man named Jack with a tenuous grip on sobriety (needless to say, it was the acting challenge of his career). He takes his family to a haunted hotel where a bunch of ghosts pause long enough in between giving each other phantasmic costumed blow jobs to convince him to kill his son, Danny, who uses his Professor X thought powers to convince Jack to kill an old black man instead and get locked outside in a fatal snowstorm.
The little boy who played Danny, 6-year-old Danny Lloyd, had no idea he was acting in a horror movie. Stanley Kubrick, a man famous for not giving one screaming banshee fart for the comfort and safety of his actors, decided to spare Lloyd from seeing all the terrifying bullshit he was capturing on film while making one of the most famous horror movies of all time (this is the same man who, on the exact same film, tormented the lead actress so badly that her hair began to fall out). Evidently he had a soft spot for children.
"And after this scene, you and the twins go to Disney World and play forever and ever and ever."
Lloyd just thought they were making a movie about a family in a hotel. He wasn't even really sure how much he was getting paid to be there. He was only ever shown severely edited footage that took out all the scary parts, which essentially means he thought he was filming the most boring snoozefest ever created, because without the iconic scenes of terror, The Shining is a movie about three people wandering around in cavernous, brooding silence.
Lloyd didn't see the actual uncut movie until many years later as a teenager, and suddenly everything clicked into place -- those two nice British girls with whom he used to play and share lunch in between takes? They were ax-murdered ghosts who wanted his soul. That nice Jack Nicholson man who did a funny tomahawk dance when Lloyd accidentally wandered on set one day? Jack was slobberingly hacking his way through a bathroom door to murder Lloyd's onscreen mother only moments prior.
"I thought we were just filming a new Tonight Show title sequence."
For all his jimmy-legged, scraggly-bearded lunacy, Stanley Kubrick did his absolute best to make sure Lloyd didn't experience any of the psychological horror he was wielding the boy to create. According to historical record, this is the closest to "doing something nice" that Stanley Kubrick ever got.
3 Ben-Hur -- Charlton Heston Didn't Know His Character Was Gay
Ben-Hur tells the story of Judah Ben-Hur (played by Charlton Heston), a Jewish prince who is betrayed by his childhood friend Messala and forced to endure a life of slavery, and it happily takes the better part of four hours to do so. Ben-Hur keeps almost meeting Jesus in a Forrest Gump sort of way, and in the end restores himself, his family, and his friends by murdering the shit out of Messala in a chariot race.
The Ten Commandments don't apply to anything you do via horses.
In spite of all its overblown spectacle (including a then-jaw-dropping ocean battle sequence that today looks like Jerry Bruckheimer playing with a bunch of toys in his bathtub), the most common criticism of Ben-Hur is focused on one key point -- Messala's betrayal seems to make absolutely no sense. These guys are supposed to be lifelong friends, and yet Messala rolls on Ben-Hur almost instantly after Ben-Hur refuses (politely but firmly) to help him find dissenting Jews now that Messala is a newly minted stickman of the Roman Empire. Why would Ben-Hur's best friend for life take away his home and family and toss him into anonymous slavery just because he refused to help Messala track down some rabble-rousers that the Romans would've eventually found on their own anyway?
Because Ben-Hur and Messala are actually former lovers, a subtext that was deliberately written into the film and just as deliberately hidden from Charlton Heston.
According to screenwriter Gore Vidal, he and the other writers were trying to think of a way to have Messala's betrayal make more sense when they came up with the "unrequited love" angle, suggesting that the reason Messala turns so instantly vicious toward his old friend is because Ben-Hur's rejection applies not only to advancing Messala's new career, but also to rekindling their previous relationship.
The director was hesitant (putting a homosexual love affair into a movie about Jesus is something no studio would do now, let alone back in the 1950s), but admitted it was a way better story than what they had and told them to go ahead with it. The filmmakers told Stephen Boyd (the actor who plays Messala) about the subplot, but Charlton Heston was kept utterly clueless because the director was convinced he'd "fall apart" if they told him. This is another way of saying that Charlton Heston could not bear the thought of pretending to be gay for a four-hour movie, so nobody told him that he was.
"No, seriously, Romans used to spit-shine each other's dicks all the time."
Boyd isn't exactly downplaying the moony gazes he throws Heston's way, so we assume Heston was simply too busy concentrating on the emotional thrust of his jaw in each scene to notice. Going back and watching the movie now, it seems impossible that Heston could've remained as heroically oblivious as he did. Yet, when he finally found out about the implicit romance years later, Heston emphatically denied that Ben-Hur ever nakedly embraced another man, saying the idea "irritates the hell out of me." Vidal shot back by vehemently backing up his claim and pointing out that Heston was the third choice for the role. Rock Hudson, an actual gay person, was initially offered the role of Ben-Hur, but his agents told him to turn it down because they thought the homosexual undertones could damage his career as a leading man -- the part was literally too gay for a gay man.