Whoever thought that a movie based on a parenting book would become such a cult hit? Tina Fey, that's who. She adapted Queen Bees and Wannabes, peppered the script with zany Saturday Night Live humor and threw in a dash of her signature non-sequitur comic touch. It was the perfect recipe for a hit. Mean Girls descended on cinemas on April 30, 2004. Fifteen years later, it's still a touchstone of popular culture. There's even a Mean Girls Day—it's October 3rd.

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Mean Girls centers around Cady Heron, a teen who spent her formative years in Africa and has never been to a North American public school. Through her eyes, the viewer sees high school for what it really is: equal parts ridiculous and frightening. Cady is recruited into a plot to overthrow the school's vicious Queen Bee, Regina George. Along with Cady, we learn that anyone has the ability to be a mean girl, from the cold hard Plastics to the art freaks. The film has a strong anti-bullying message, but as uncool as it is to be a mean girl, it's sure fun to speak like one. Mean Girls is one of the most quotable movies of the twenty-first century.

"I'm Not Like A Regular Mom. I'm A Cool Mom."

Some people are done with high school the moment they throw their graduation caps in the air; others act like they've never left. Amy Poehler is pitch-perfect pathetic as Mrs. George, Regina's mom, who embodies the latter. She clings to her youth like a botoxed barnacle. As hilarious as she is desperate, Mrs. George earns her 'cool mom' status by serving fluorescent mocktails to the Plastics—alcohol optional—and allowing her youngest daughter to mimic a Girls Gone Wild video.

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Perhaps most notably, Mrs. George memorized the Plastics' risqué choreography to "Jingle Bell Rock," which she performs in the aisles at the Winter Talent Show. In Mrs. George's "cool mom" world, she's forever sixteen and happy hour is from four to six.

"That's Why Her Hair Is So Big. It's Full Of Secrets."

Damian and Janis, the "art freaks", pride themselves on being Cady's North Shore High safari guides. This means familiarizing Cady with the local predators: the Plastics. Each Plastic gets her own colorful commentary and while Janis' is dripping with vitriol, Damian's is dry with the slightest hint of admiration. This description of petite busybody Gretchen Wieners is hands-down the most memorable.

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Irony abounds in Mean Girls. Damian and Janis hate the Plastics, but can't stop obsessing about them. On the flip side, Gretchen has everything—her father is the inventor of Toaster Strudel—but is insecure and forever paranoid it'll all be taken away. Collecting dirt on anyone and everyone is like Gretchen's safety vest. And if it gives her supermodel hair...bonus.

"Don't Have Sex. Because You Will Get Pregnant And Die."

Though the film's subject matter is predominantly the titular mean girls, it can't resist taking a few potshots at the lunacy that is most high school sex-ed. The goal of these programs seems to be scaring teens into not having sex. This usually involves pregnancy horror stories and graphic photos.

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Mean Girls doesn't have time for an entire full-length class with Coach Carr—though it would be hysterical—so sex-ed is summed up in this one iconic line. While Coach Carr may not know how to spell "chlamydia", he's hip to the fact that none of these scare tactics actually work. He concludes the class by handing out condoms.

"We Should Totally Just Stab Caesar!"

In the world of the Plastics, or "Girl World", Cady tells us that all the fighting needs to be sneaky. Girls aren't allowed to vocalize any feelings of malcontent with their friends, no matter how badly they're treated. Gretchen relishes her status as Regina's primary lady-in-waiting, but Regina's increasing nastiness begins to take its toll.

Of course, Gretchen can't actually stand up for herself. That's why she takes her frustration out on her English report. In this thinly-veiled metaphor, Gretchen's the "just as cute" Brutus and Regina is the tyrannical Caesar. Only in Girl World would Caesar and Brutus have BFF necklaces.

"One Time, She Punched Me In The Face. It Was Awesome!"

Damian says, "If North Shore was Us Weekly [the Plastics] would always be on the cover." Inwardly, everyone loathes the Plastics but outwardly, the masses jockey for their acknowledgement...in any form. For the star-gazers of North Shore, and Bethany in particular, being physically assaulted by Regina George is preferable to being ignored by her.

Bethany isn't the only one starstruck by the Plastics. Students from every clique (and even some teachers) dish about them as if they're Hollywood celebrities. These abused admirers even nominate most of the Plastics for Spring Fling Queen.This type of idolatry is maddening to the viewer, but that's what makes it so satisfying when Regina gets clobbered by the bus. She lives, but proves that karma is the ultimate Queen Bee.

"You Can't Sit With Us!"

The ultimate social kiss of death. Nobody worships Regina more than Gretchen, but when Regina's knocked down a peg, Gretchen is quick to throw her away like yesterday's cheese fries. This really exposes the true nature of the Plastics' friendship—or lack thereof.

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Regina puts on a few pounds—she's sabotaged by Cady—and can only fit into sweatpants. This is strictly against Girl World rules, which dictate sweatpants may only be worn on Fridays. Obviously, real friends would be accepting of each other no matter their weight or wardrobe. This line is so funny not just because of Gretchen's screechy delivery, but because it hits the nail on the head of what it means to be a mean girl.

"That Is The Ugliest Effing Skirt I've Ever Seen."

Why is Regina allowed to get away with her reign of terror for so long? Because, on the outside, she's sweeter than a Disney princess. She only lets her Cruella side out behind closed doors. Cady is initially snowed by Regina's outwardly pleasant demeanor...until she spends actual time with her.

At school, Regina compliments a girl on her skirt. As soon as the girl is out of earshot, Regina utters this bon mot to Cady, making Cady recall a similar interaction regarding her bracelet. If Regina were a comic book villain, her name would be Two-Face. Wait, is that taken?

"On Wednesdays, We Wear Pink."

Of all the Girl World rules, this is the most notorious. Probably because it's the most ludicrous of the bunch. It's pushed into comedy gold when the non-girly Cady has to scramble to find something pink to wear. She has to settle for swimming in Damian's extra-large baby-pink polo. These rules just demonstrate that the Plastics are sheeple, like everybody else.

For the uneducated, the other rules are as follows: "You can't wear a tank top two days in a row. You can only wear your hair in a ponytail once a week. We only wear jeans or track pants on Fridays." And don't even think about wearing a vest.

"That Is So Fetch."

As desperate as Gretchen is to be a clone of Regina, there's also a small part of her that wants to stand apart from her dictator. That's why she invents the word "fetch", insisting it's "like, slang, from England." She tries to insert it into every conversation, with the subtlety of a dancing grizzly bear.

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Regina quickly grows tired of "fetch" and rips into Gretchen, rudely decreeing that "fetch" will never happen. But Gretchen would have the last laugh, as the term has been permanently solidified into the pop culture vernacular. Her father may have made Toaster Strudel happen, but Gretchen made "fetch" happen.

"Boo, You Whore."

While the Plastics may treat their adoring public with saccharine syrupiness, they don't always show each other that "respect". When Karen (poorly) fakes a cold to get out of spending time with Regina, Regina fires back with this gem. For Karen, it particularly smarts because she just received confirmation that Regina has been calling her a slut behind her back.

Later in the film, Ms. Norbury admonishes the girls for calling each other demeaning, misgoynistic names. She's totally right, but her strong stance isn't enough to shut down this iconic line. It has since taken on a life of its own. People all over the world reference it when friends say they're unavailable. Who needs to rule North Shore High? Regina George rules the world.

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