Sixteen Candles. Ferris Bueller's Day Off. Clueless. All staples of sleepovers, and rightfully so — they're funny, relatable, and oh-so-quotable.

But there's one teen movie that tops them all, perfectly encapsulating the thrill of being a high schooler: 10 Things I Hate About You, which came out 20 years ago this month. Yes, the movie that introduced Heath Ledger to the masses, made us all shed a tear during Julia Stiles' emotional poem recitation, and inspired many to start a petition to get Save Ferris to play at their prom, has been around for two decades. When and how did us '90s kids get so old?

10 Things I Hate About You is a movie where everything — cast, soundtrack, setting, and script — all just works. A loose adaptation of William Shakespeare's Taming of the Shrew, 10 Things focuses on the Stratford sisters, Bianca and Kat. Bianca can't date until her older sister does, but Kat is too busy being annoyed by everyone and trying to smash the patriarchy to bother with men. Knowing this, Bianca's would-be suitors Joey and Cameron enlist the brooding Patrick to date Kat so they can court Bianca. Teen drama — with a healthy dose of comedy, sisterly bonding, and life lessons — ensues.

If you're not already sold, here are 10 reasons why 10 Things I Hate About You is the greatest teen movie ever:

1. The cast was perfection. The casting department knocked this one out of the park, hiring the right YM-cover ready actor for each role, from Larisa Oleynik (Alex Mack forever!) as the popular Bianca to Joseph Gordon-Levitt as semi-dork Cameron. Julia Stiles gave Kat her tough edge, while '90s heartthrob/villain Andrew Keegan was perfectly awful as teen model Joey. (Of course, Heath Ledger was the brightest star of all, but we'll get to him later.) The adults, including Allison Janney as a guidance counselor writing smut during the school day and Larry Miller, Bianca and Kat's extremely overprotective OB/GYN dad, were also fantastic in their roles. The entire cast gelled.

2. The script is still funny. Some movies do not age well, but 10 Things (mostly) holds up. There are a few cringey moments, like when Bianca uses the R-word, or when Kat flashes the soccer coach to get Patrick out of detention (I know, WTF), but overall the movie is funny and touching — though never maudlin — when it needs to be. The banter between Kat and Patrick is relatable to anyone who has had a secret crush, while the rumors about Patrick's history are fun (no, he doesn't know Marilyn Manson, and he's pretty sure he didn't sleep with a Spice Girl).

3. You wanted to steal all of their clothes. The outfits in this movie are so '90s it hurts. Chunky Mary Janes! Tiny clips in the hair! Lots and lots of shirts with collars! These are the clothes we wore to school, the movies, and the mall. Were you really fully dressed if your midriff wasn't showing?

4. The soundtrack is ska-riffic. There are some serious bops in this movie. The soundtrack features The Cardigans, Madness, and George Clinton, and both Save Ferris and Letters to Cleo perform in the film. The latter somehow managed to hold a concert on the roof of the high school, which makes zero sense but did produce a great visual.

5. It introduced Shakespeare to a new audience. Sometimes, you have to sneak in some learning. While Baz Luhrmann in 1996 used the original dialogue in his modernization of Romeo + Juliet, 10 Things writers opted to lightly sprinkle Shakespearian quotes throughout their movie. Cameron declares, "I burn, I pine, I perish," when he first spies Bianca. If this random sentence piqued your teen curiosity in 1999, a mere 32 hours of waiting for AOL to connect could have revealed its Shakespearean origin. Bam! Learning achieved.

6. Their high school was amazing. If every school in America looked like Padua High, we wouldn't have any issues with truancy. The building is really Stadium High School in Tacoma. Originally designed as a hotel, in the early 1900s it was made into a public school. It's stately, with a great stadium (hence the name) and views of the water. Padua High is almost its own character, and it's possibly the prettiest one of all.

7. Kat didn't back down. Though badgered by her peers for her fierce feminist views, Kat holds firm to her beliefs and is unabashedly herself. Kat's abrasiveness never masks her wit and confidence, and she never lets go of the magical gift she has: the ability to not care about what other people think.

8. That Heath Ledger serenade scene. The film's best moment comes courtesy of Patrick and his microphone. In an attempt to win Kat over, he bribes the band to play Frankie Valli's "Can't Take My Eyes Off You" to serenade her during soccer practice. You might think Kat would be totally turned off by this very public display of affection, but you'd be wrong — she laughs and smiles, and after Patrick ends up in detention, flashes the teacher to get him out (remember that from before? Still creepy).

9. Kat's sonnet that was actually just a poem, but whatever. There are some contenders for the film's second best scene — the out-of-control party at Bogey Lowenstein's house, the prom where Bianca decks Joey — but without Kat reading her poem about Patrick in front of their English class, our movie wouldn't have a title. The assignment was to write a sonnet (remember, Shakespeare) but Kat actually wrote a regular old poem (whoops). While listing 10 reasons she loathes an unnamed someone (clearly Patrick), she breaks down, realizing she hates "the way I don't hate you, not even close, not even a little bit, not even at all." Stiles told Cosmopolitan UK her tears were "not intentional," and she "never expected [she] was going to start crying." It's an authentic, moving moment.

10. It turned Heath Ledger into a star. He'd appeared in television shows and movies in his native Australia, but most Americans were introduced to Heath Ledger in 10 Things I Hate About You. No one else could have played this role as Ledger did, exuding a casual charisma. He had a wide smile that lit up his entire face, and gave bad boy Patrick a heart. Of course, his career exploded after 10 Things, as it should have — he was an incredible actor. 10 Things I Hate About You was his stepping stone to worldwide fame, and for that, this movie is aces.