It is a truth universally acknowledged by devoted moviegoers that any film, no matter how realistic, requires its audience to maintain a certain suspension of disbelief. Witness the action hero outrunning a fireball in defiance of all known laws of physics, or the newlywed couple who never even try the light switches in their obviously haunted house.

But sometimes it's worth it to take a step back and give our favorite films a good fact-checking, as with these five moments from some of the best movies of 2013; moments which really stretched the limits of reasonable belief. And, because movies are fiction, we created two fake facts of our own. See if you can guess which ones:

"Gravity"
Credit goes to director Alfonso Cuarón for pointing out the biggest inaccuracy in his own film. Namely: as much as we all enjoyed the spectacle of Sandra Bullock's space-station stripdown to her briefs, a real-life astronaut would have emerged from her spacesuit wearing an adult diaper.

"American Hustle"
David O. Russell's critically acclaimed movie is based on the true story of an FBI sting in the 1970s. But it loses authenticity at the moment when a heated argument between Jennifer Lawrence and Amy Adams ends with a passionate kiss, when everyone who's ever been in a bathroom catfight knows that they end with somebody getting a swirlie.

"The Hunger Games: Catching Fire"
Although the source material had Johanna Mason getting full-on naked in an elevator, Jena Malone's Tribute Parade costume in "Catching Fire" was way too complex to be removed singlehandedly over the course of an elevator ride. According to Malone's interview with Vulture,she "would have needed like a 500-story elevator, someone working the buckles of my shoes — yeah, I would have needed a whole army of midgets to help me."

"The Wolf of Wall Street"
One of the film's most outrageous scenes, in which hedge fund honcho Jordan Belfort goes for a joyride whilst high on Quaaludes, is obviously unrealistic... because according to Belfort's memoir, the car he was driving was a Mercedes, not a Lamborghini.

"World War Z"
Zombie apocalypse? No problem. A chase scene in which only Brad Pitt and his family manage to escape the marauding corpes? Sure. An army of the undead piling on top of each other in order to clear a 100-foot-high wall? Seems reasonable. But come on, you guys: that stowaway zombie on the plane would never have cleared airport security.

Real Mistakes: "Gravity," "The Hunger Games: Catching Fire," "The Wolf of Wall Street"

Fake Mistakes: "American Hustle," "World War Z"