You’d be hard-pressed to find a true cinephile who doesn’t own a copy of Harold and Maude. The 1971 box office failure, directed by Hal Ashby and written by Colin Higgins, has become a Hollywood classic since its rocky debut. A brutally dark rom-com, Harold and Maude tells the story of a death-obsessed young boy (Bud Cort) who falls for a free-spirited 79-year-old woman (Ruth Gordon), much to the chagrin of his oblivious, blue-blooded mother (Vivian Pickles). Not only has the film found a second life at film festivals, outdoor park screenings, arthouse cinemas, and on home video, but it’s also become a must-see movie for anyone serious about filmmaking. Here are 10 things you might not know about the film that pushed the boundaries of May-December romances.

1. BUD CORT NEARLY KILLED HIMSELF WITH HIS METHOD ACTING.

On the Harold and Maude set, Bud Cort was infamous for his Method acting. In an interview with The Guardian, Cort shared that among the many scenes he improvised were his breaking of the fourth wall to give a cheeky glance at the camera and raising his middle finger at Vivian Pickles during her entire monologue after she tells him he’s joining the army. As further proof of his intensity, Cort described his commitment to the opening fake suicide scene, saying, “I was so into it that I believed I was hanging myself to death.” In Being Hal Ashby, author Nick Dawson shared more instances of Cort’s devotion to the character, writing that during Harold’s fake drowning scene, “Cort lay face down in the heavily chlorinated water of the Rosecourt swimming pool for take after take until he could no longer keep his eyes open.”

2. BUD CORT REFUSED TO DO PUBLICITY IF THE STUDIO DIDN’T GIVE HAL ASHBY CREATIVE CONTROL OVER THE EDIT.

During post-production, Paramount Pictures stripped Ashby of his power to edit the film. Thus, in solidarity with his director, Cort told the film’s PR team that he wouldn’t do any publicity for the film unless Ashby got his movie back. According to The Guardian, control over the footage was handed back to Ashby—save for a kissing scene between Harold and Maude that Paramount head honcho Robert Evans despised.

3. ACTRESS ALI MACGRAW, ROBERT EVANS’ THEN-WIFE, WANTED THE LOVE SCENE BETWEEN HAROLD AND MAUDE TO BE CUT.

Of course, her Paramount boss husband tried to oblige. Ashby furiously objected, saying, “That’s sort of what the whole movie is about, a boy falling in love with an old woman; the sexual aspect doesn’t have to be distasteful.” About the less-than-explicit scene, Being Hal Ashby author Nick Dawson wrote, “Ashby wanted to show the beauty of young and old flesh together, something that he knew the younger generation, the hippies, the heads, the open-minded masses would dig, but Evans said it would repulse most audiences, so it had to go.” In the end, Ashby won by sneaking the footage into the film’s trailer.

4. VIVIAN PICKLES BROUGHT HER OWN CLOTHES FOR MRS. CHASEN’S WARDROBE.

Pickles, who played Harold’s detached, socialite mother, flew in her own costumes for the character. “I had brought some of my own clothes over from England, which we had altered, and, in the week before shooting began, I shopped endlessly for the rest with the costume designer, Bill Theiss,” wrote Pickles for The Criterion Collection. “He was spot-on … He kindly raided his mother’s jewelry box to borrow antique jewelry for Mrs. Chasen.”

5. HARRISON FORD WORKED FOR SCREENWRITER COLIN HIGGINS—AS A CARPENTER.

Here’s a fun fact separate from the production of the film: According to The Criterion Collection cut, Colin Higgins employed Harrison Ford, then working as a carpenter, to build a hot tub and deck for his backyard.

6. BUD CORT AND RUTH GORDON’S REAL-LIFE RELATIONSHIP ALMOST MIRRORED THAT OF THEIR CHARACTERS.

In the April 2001 issue of Vanity Fair, Cort revisited the cult classic and reminisced on his chemistry with his co-star. “During the making of the film, [Ruth] was very standoffish. Then, the day my father died, the first call I got was from Ruth, saying 'Let me tell you about the day my father died,’” he told the magazine. “And suddenly we became the characters pretty much that we were in the film. We really became friends the night my father died. Oddly enough, he died waiting for me to show up on This is Your Life, Ruth Gordon.

7. ONE OF THE FILM’S LOST SCENES INVOLVED HAROLD SERVING UP HIS OWN HEAD.

“It opened up with a shot of a large, silver-plated serving dish," Colin Higgins told Film Quarterly in 1972. "A hand comes in and removes the cover and there, on a little bed of parsley, is Harold's head. Two hands come into the frame and pick up the head, and we move back and there's Harold holding his head and looking at it. He sort of peels off the latex blood and walks over to his bedroom chair where a headless dummy sits. He puts the head on the dummy, but the head really isn't sitting right, and he goes into the closet to find something.” Of course, that scene never made it into the theatrical cut.

8. ELTON JOHN PASSED ON DOING THE SOUNDTRACK.

According to The Criterion Collection version of the film, producer Charles Mulvehill initially approached Elton John to write the music for the movie, as Ashby was a fan of the pop star. John passed—but not before suggesting his friend, Cat Stevens, for the job.

9. HAROLD AND MAUDE WAS BASED ON COLIN HIGGINS’ THESIS FILM AT UCLA.

At the time, Higgins was working as producer Edward Lewis’ pool boy. According to Being Hal Ashby, Lewis’ wife loved the script so much that she got her husband to give it to Stanley Jaffe at Paramount. At first, Higgins was going to direct the film, but screen tests proved to the studio that he wasn’t ready. Thus, Hal Ashby was brought on.

10. HAL ASHBY ALMOST WITHDREW FROM THE FILM A MONTH BEFORE SHOOTING BEGAN.

Frustrated with several issues he was having with the studio, including not being able to hire cinematographer Gordon Willis, Ashby considered leaving the picture altogether. “My creative juices have indeed finally been tapped and it would, I’m afraid, have to take its toll on the film, and Harold and Maude deserves better,” Ashby wrote to Robert Evans. “I feel like I could make the film as funny as the Vietnam War.”