We asked the BuzzFeed Community for the worst movie inaccuracies they've ever noticed before. Here are the mind-melting mistakes.
1. In Titanic, Jack mentioned that he went ice fishing on Lake Wissota, but that lake wasn't formed until 1917, five years after Titanic sank.

Paramount Pictures
2. In Mean Girls, Cady was from Africa, but the picture in her room was of her atop an Asian elephant, not an African one.

Paramount Pictures
3. In The Wizard of Oz, after the Scarecrow got a brain, he incorrectly stated the Pythagorean theorem.

MGM
In fact, the theorem states: “The square of the hypotenuse of a right triangle is equal to the sum of the squares of the other two sides”
—Amy Susan Fisher, Facebook
4. In Lucy, Professor Norman stated that humans only use 10% of their brains, but real neurologists confirmed that virtually every part of the brain is always in use.

Universal Pictures
5. In Never Been Kissed, the math club's giant poster incorrectly recited the number pi.

Fox 2000 Pictures
It's actually 3.14159.
6. In the Twilight series, Edward was a vampire, which meant he couldn't have a heartbeat or an erection, but he was somehow able to have sex with Bella.

Summit Entertainment
And even though his body temperature was so low, which would impair all sperm production, he somehow impregnated her.
7. In Braveheart, the movie took place in the early 14th century, but the characters wore kilts, which weren't even created until hundreds of years later.

Paramount Pictures
8. In The Shawshank Redemption, Andy escaped prison in 1966 via a tunnel that was covered up by a poster of Raquel Welch from the movie One Million Years B.C., but that movie wasn't released until 1967.

Columbia Pictures
9. In the Star Wars series, every single planet magically had the same exact gravitational force, but in reality that'd be impossible.

Lucasfilm Ltd.
10. In It's a Wonderful Life, Clarence revealed that George's brother died at the age of 9, but the dates on his gravestone said that he was only eight.
RKO Radio Pictures
11. In The Aviator, Leo DiCaprio's character requested 10 chocolate chip cookies, but chocolate chip cookies weren't invented until 1930, two years after this scene would have taken place.

Warner Bros. Pictures
12. In Leap, one scene showed the construction of a green Statue of Liberty, but in reality the Statue of Liberty should have been brown.

Entertainment One
The Statue of Liberty (made of copper) was erected in 1886 but didn't fully turn green until 1920.
13. In Inception, Earnes used the defibrillator to bring Fischer back to life, but defibrillation would actually be ineffective on someone who's flatlining.

Warner Bros. Pictures
Technically speaking, a flatline is known as "asystole," and when it happens there's no electrical activity left in the body to reset with a shock. That's why the defibrillator won't work.
14. In The Karate Kid, kicking an opponent in the head is an illegal move and would be grounds for disqualification in any tournament, yet that's exactly how Daniel won.
Columbia Pictures
15. In My Cousin Vinny, a surprise witness was called to court, but in real life all witnesses must be announced beforehand.

20th Century Fox
16. In Doctor Strange, Dr. Strange and Dr. Palmer performed brain surgery without wearing surgical masks, but in real life they're required in all operating rooms.

Marvel
17. And in Gravity, Sandra Bullock's tears floated off of her face as she cried...
Warner Bros. Pictures.