1. Janis Ian is the name of a real-life singer and songwriter, who memorably wrote the song “At Seventeen.” (If you’ve ever been to a lesbian karaoke bar, someone will sing that song.) This song plays in the background during a fight at Regina’s house. The Janis Ian name-drop is a reference to the fact that Ian was the first-ever musical guest on SNL and an out lesbian in real life.

2. Also, Janis mentions toward the end of the film that she’s “Lebanese.” This is probably why “lesbian” rumors spread about her during middle school, when eighth graders didn’t know the difference between the two words. This is why you should pay attention during Geography class, kids.

3. Last lesbian fact: Although Lizzy Caplan doesn’t get to be a lesbian in this film, Caplan came with previous lesbian thespian experience. In the TV show Once and Again, she played Mischa Barton’s ex-girlfriend in two episodes. (Barton would, of course, dip her acting toes back in the Sapphic waters during The O.C.)

4. Straight people things: In real life, Lizzy Caplan has been in a relationship with Matthew Perry since 2006, meaning that Janis Ian and Chandler Bing do it on a regular basis. Could you be picturing this any harder right now?

5. Just kidding, one more Sapphic connection: At the prom, Cady mentions that she “knows” one of the songs that’s playing, a reference to her general pop cultural illiteracy. (Africa and shit, y’know?) That song is “Built This Way,” a track by Samantha Ronson, the British DJ Lindsay Lohan would confirm she was dating four years later.

6. Lindsay Lohan was originally going to play Regina but was worried that the public would associate her with being a “bitch,” so she made Lorne Michaels switch her part. The producers originally cast Amanda Seyfried as Cady, but Michaels felt she would be a better Karen. (Maybe because her breasts can always tell when it’s raining?) As Chabert was born to play Gretchen Wieners, she always had that role.

7. Before playing Gretchen, Chabert was a prolific voice actress, in addition to her role on Party of Five. Her most prominent voiceover gigs include playing Eliza in The Wild Thornberrys and the original Meg in the first season and a half of Family Guy. After the character was slightly rewritten in the second season, Mila Kunis took over Meg duties.

8. Regina George’s character was partly inspired by Alec Baldwin from Glengarry Glen Ross. Fey worked with Baldwin extensively on SNL, as he has hosted the show more than anyone else in history, and apparently liked working with him so much that she cast him as Jack Donaghy in 30 Rock. This is a show in which he plays yet another riff on his Glengarry Glen Ross character.

9. Rachel McAdams had to wear a wig while filming Mean Girls, presumably because her mother’s chest hair was unavailable for loan.

10. Amy Poehler is only seven years older than Rachel McAdams, who plays her daughter in the film. McAdams was eight years older than Lindsay Lohan, who was the only Plastic still young enough to be playing a high schooler by the time the film was released.

11. Lindsay Lohan’s character Cady is named after Elizabeth Cady Stanton, early feminist and groundbreaking foremother of the Women’s Rights Movement. If she were alive, Stanton also would have loved Ladysmith Black Mambazo.

12. Daniel Franzeze’s character, Damien, was based on an old friend of Tina Fey’s, who is now a writer for TV Guide. Glen Coco is also a real-life friend of Tina Fey, and Mrs. Norbury was named after Fey’s old German teacher. Lesson: You need to know Tina Fey, so you can be a character in one of her movies.

13. Despite the fact that the movie was set in Evanston, Illinois (#northshorerepresent), the entirety was filmed in Canada, the nation of Rachel McAdams’ birth.

14. When Tim Meadows (who plays the principal) walks through the school with a baseball bat in the “the girls have gone wild!” scene, he says, “I did not leave the South Side for this!” This is a direct quote from the movie Lean on Me, a movie about a principal struggling to improve a decaying school.

15. Mariah Carey, who has stated numerous times that she’s a huge fan of the movie, directly quotes Mean Girls in the intro to the song “Obsessed.”

16. There was a video game version of Mean Girls adapted for PC and Nintendo DS — that I sadly have not played. I assume in that version, Trang Pak still made out with Coach Carr.

17. The director of Mean Girls, Mark Waters, is actually the younger brother of screenwriter Daniel Waters. Daniel Waters would become infamous in the 1990s for winning Worst Screenplay Razzie Awards for both Hudson Hawk and The Adventures of Ford Fairlane, but before that, he wrote the screenplay to Heathers. Heathers is the movie most credited as being a direct influence on Mean Girls, as it featured a group of four popular girls wreaking havoc on the lives on those around them. Cady even briefly references that film.

18. Jonathan Bennett (who plays Aaron Samuels) was cast in the movie at the urging of Fey, who thought he looked like Jimmy Fallon, and Mark Waters’ wife and daughter, who thought he was “fetch.” However, audiences have not found him quite as fetch since Mean Girls ended, as his major film credits have included Bachelor Party: Vegas, Cats Dancing on Jupiter, National Lampoon’s Van Wilder: Freshman Year and Dukes of Hazzard: The Beginning. His biggest film, Morning Glory, allowed him to reteam with Rachel McAdams in the prestigious role of “Unnamed Interviewee.” If it’s any consolation to Mr. Bennett, almost every girl I know will think he’s “grool” forever.

19. Mark Waters had previously directed three films before Mean Girls, and the most successful of them was Freaky Friday, the surprisingly acclaimed 2003 film starring La Lohan. Oddly, it also grossed more money in the theatres than Mean Girls did, which makes no logical sense. His next film will be an adaptation of Sabrina, the Teenage Witch, which (I hope) will secretly be Mean Girls 3.

20. The movie was inspired by Queen Bees and Wannabes by Rosalind Wiseman, a non-fiction guide for parents to “[help] your daughter survive cliques, gossip, boyfriends and other realities of adolescence.” (Tina Fey said she found it “funny.”) The film was (obviously) loosely based on the book. However, at least one element was taken directly taken from it: Regina means “queen” in Romanian, Italian and Latin.

21. Although it has a Facebook page, P.J. Calamities is (unfortunately) not a real bar in Evanston. However, Old Orchard Mall is a thing, despite the fact that it’s an outdoor mall and not an indoor one, like in the movie.

22. The Barnes and Noble in Evanston is located right in the middle of Evanston. So, if Gretchen got diarrhea in it, she would be happy to run into almost everyone she knows afterward.

23. In the scene when Cady asks for the “lavatory pass,” you can see the periodic table on the board behind them. On it, the table lists “silicone” as one of the elements. This is not an actual element, although “silicon” is. Instead, it’s likely a sly reference to Mrs. George’s rock-hard breasts.

24. The film initially earned an R rating from the MPAA for language and sexual content. To get a PG-13, numerous plot elements and verbal exchanges had to be toned down or taken out. In the original script, Jason was to ask Cady, “Is your cherry popped?” during the lunch-time poll scene, and that burn-out girl did way more than make out that hot dog. (See: Masturbation.) And when Cady walks in on Jason and Gretchen making out at her party? The R-rated version had Gretchen giving him a big ol’ beej.

25. For the Kevin Gnapoor’s rapping scene, Tina Fey and Amy Poehler taught actor Rajiv Surendra how to rap. They recently recreated it for the internet, proving that Mean Girls truly is the gift that keeps on giving.