Ferris Bueller’s Day Off just turned 30. Yes, the ultimate high school movie has officially outgrown its twenties. The Matthew Broderick-helmed ode to Chicago, charisma, and truancy was written, directed, and produced by John Hughes, the same man behind other ’80s teen favorites, including The Breakfast Club, Sixteen Candles, and Pretty in Pink. In addition to effectively breaking the fourth wall, Ferris Bueller’s Day Off became Hughes’s highest grossing domestic release of all time. More importantly, it supplied a generation’s worth of ’80s kids with inspiring yearbook quotes and slacker inspiration. In honor of Ferris Bueller and the fact that movie fandom—like high school—never ends, we’ve assembled a list of 20 things you didn’t know about the iconic film, with help from IMDb.

1. John Hughes wrote the first draft of Ferris Bueller’s Day Off in six days.

2. The films takes place on one day; specifically, June 5, 1985.

3. Cindy Pickett and Lyman Ward, who played Ferris’s parents, married in real life after filming the movie.

4. Clearly, love was in the air for the Bueller family: even though they played siblings, stars Matthew Broderick and Jennifer Grey would later become engaged after meeting on set.

5. To produce the desired drugged-out effect for his role as the drug addict in the police station, Charlie Sheen stayed awake for more than 48 hours before the scene was shot.

6. The fictional Shermer High School is a pivotal location in Ferris Bueller’s Day Off, Breakfast Club, and Sixteen Candles. But Ferris Bueller’s Day Off actually features an exterior shot of Hughes’s own high school, Glenbrook North High School.

7. Alan Ruck was 29 years old when he played the role of teenager Cameron.

8. Most of the license plates in the film are abbreviations for titles of movies by John Hughes. Katie’s = VCTN (National Lampoon’s Vacation); Jeannie’s = TBC (The Breakfast Club); Tom’s = MMOM (Mr. Mom); Rooney’s = 4FBDO (Ferris Bueller's Day Off). The exception is Cameron’s Ferrari, with a license plate that tellingly reads NRVOUS.

9. At one point in the film there was a line that Ferris was going to say about how “come next year, I’ll be the first kid to ride on the Space Shuttle.” It was even featured in the preview for theaters. However, less than five months before the film’s release on Jan. 28, 1986, the Challenger exploded 73 seconds after launch, resulting in the deaths of all seven people aboard. On account of this tragedy, John Hughes had the preview recalled from theaters and the line was edited out of the final film.

10. The shot of Ferris playing the clarinet was done on the spot. Someone spotted the instrument as part of the set and Matthew Broderick said he could play it, which of course he couldn’t.

11. Ferris changes nine times before ever leaving the house.

12. John Hughes can be seen in a tiny cameo in one of the early Chicago downtown montage sequences, climbing across traffic, from right to left of screen, wearing a light blue jacket and big ’80s hairdo. Hughes has another unplanned appearance in the film: the hand that presses the speaker button on Cameron’s phone belongs to the director himself. When the crew left, Hughes took the camera and shot the scene since no one else was getting it right.

13. Rob Lowe, John Cusack, Jim Carrey, Johnny Depp, Tom Cruise, Robert Downey Jr., and Michael J. Fox were all considered for the role of Ferris Bueller.

14. Anthony Michael Hall turned down the role of Cameron to avoid being typecast. Meanwhile, Molly Ringwald allegedly wanted the part of Sloane, but was denied by Hughes, who told her that the part wasn’t big enough for her. A competing rumor claims that Hughes didn’t think Ringwald was elegant enough for the role, and found Mia Sara more refined.

15. The Ferrari belonging to Cameron’s father wasn’t a real Ferrari. Because it was too expensive to rent one, three replicas were made—using an MG chassis—each with a fiberglass body.

16. The synchronized dance set to “Twist and Shout” borrows from Michael Jackson’s “Thriller” choreography.

17. The band Rooney is named after the principal in the movie, Ed Rooney. The ska punk group Save Ferris similarly took its name from the Hughes flick.

18. There is a poster for Simple Minds’ song “Don’t You Forget About Me” on Ferris’s wall, a track that was previously immortalized in 1985’s The Breakfast Club.

19. Ferris’s line about Cameron’s house being very pretty and very cold was originally supposed to be said by Allison in The Breakfast Club regarding her home life.

20. Pretty In Pink also came out in 1986. Together, Pretty in Pink and Ferris Bueller’s Day Off grossed more than $110 million that year.

21. Whenever Mr. Rooney and Ferris have a conversation with each other, only one of them speaks throughout the entire conversation; the other is completely silent.

22. John Hughes told Ben Stein, who had a degree in economics, to present an actual economics lecture in his scenes. Hence nothing Stein says (aside from the roll call) is scripted.

23. The Cubs game depicted in the movie that Ferris and his friends attend was an actual game played against the Atlanta Braves on June 5, 1985.

24. In earlier drafts of the film, Ferris had two additional younger siblings. When it came time to edit, the final draft actually has evidence that Ferris does in fact have younger siblings, such as drawings on the fridge and a family photo seen in his dad’s office.

25. The drawing on the refrigerator in the Bueller’s kitchen is actually a drawing of John Hughes, drawn by his 6-year-old son.

26. The Ferrari was originally supposed to smash through the window of the garage and land in the backyard. Unfortunately, it over-shot its mark and hit a fence that was dividing the house from the yard next door.

27. The final scene in the garage was shot in early fall, so each of the leaves on all the trees outside had to be hand-painted green every morning before shooting. In the shot looking up from the wreck at the three friends, the reflection of a yellow tree can be spotted in the window.

28. While a rumored sequel was much-discussed, Matthew Broderick ultimately felt that the film didn’t need a sequel, and that the movie was about a specific time and place and didn’t need updating. However, Broderick did agree to a Ferris Bueller Honda commercial for the 2012 Super Bowl.

29. Ferris’s synthesizer is an E-mu Emulator—which in 1985 would have cost $8,000.

30. In early drafts of the script, Sloane’s last name was “Tandy.” She was eventually re-named after Sloane Tanen, daughter of then-Paramount head Ned Tanen.