In 1955, Vladimir Nabokov wrote about a predatory middle-aged literature professor who succumbs to his desires for the flesh and fancy of a 12-year-old girl he nicknames Lolita. The novel went on to become one of the most controversial works of the 20th century. A few years later, Stanley Kubrick directed the most successful adaptation of Lolita, despite naysayers who said it simply couldn’t be done. More than 50 years later, Kubrick’s film, starring Sue Lyon as the precocious girl, still gets people talking thanks to its stellar performances (Peter Sellers was nominated for a Best Supporting Actor Golden Globe) and, of course, Nabokov’s scintillating material. Here are 20 things you might not know about the film.

—Public fascination with the details of Kubrick’s casting partially inspired the crew to film overseas where they could keep a lower profile. Also, many of the sponsors were British, and Kubrick had a fear of flying.

—Kubrick makes an accidental cameo in the film in the opening, just before Humbert opens the door. You can see the director walking out of the shot.

—Kubrick wanted James Mason for the role of Humbert from the start, but he initially turned it down due to a previous Broadway engagement. Other actors considered the role: Laurence Olivier, Errol Flynn, Peter Ustinov, and David Niven.

—Actresses considered for the role of Lolita include: Tuesday Weld, Hayley Mills, Joey Heatherton, and Jill Haworth. Lolita Author Vladimir Nabokov agreed with Kubrick that Sue Lyon was right for the role, but years later stated that Catherine Demongeot would have been the ideal Lolita.

—Lolita author Vladimir Nabokov, who wrote the screenplay for the film, turned in a script that ran 400 pages and called for a seven-hour film. Kubrick and producer James Harris had to alter it significantly. The unused screenplay deviated from the novel and featured a Hitchcock-like cameo for Nabokov, who is referred to as “that nut with a butterfly net.” He later published the complete script in 1974 as Lolita: A Screenplay .

—Kubrick wanted the character Clare Quilty to have a New York accent and had Peter Sellers model Quilty’s voice after his friend Norman Ganz, a jazz impresario, who had a loud voice with a lisp.

—Due to Peter Sellers’ strong improvisational skills, the personality of his character Quilty was formed on the set during the shoot. Sellers said of the role:

Quilty was a fantastic nightmarish character, part homosexual, part drug addict, part sadist, part masochist, part anything twisted and unhealthy you can think of. He had to be horrifying and at the same time funny. I had never met anyone at all like this so I just had to guess, to construct an imaginative idea for myself of what such a person must be like. When I saw myself on the screen, I thought ‘This time you’ve done it – no one will ever believe this.’ But then in the U.S. I actually ran into a couple of people who might almost have been role models for the character and I began to think, ‘Oh, well, perhaps you weren’t so far out after all.’

—Kubrick shot Peter Sellers’ scenes with two or three cameras at the same time since Sellers’ first takes were best. The director wanted to ensure he captured the performance from all angles.

—Kubrick only had one regret about the film:

She was actually just the right age. Lolita was twelve and a half in the book; Sue Lyon was thirteen. I think some people had a mental picture of a nine-year-old. I would fault myself in one area of the film, however; because of all the pressure over the Production Code and the Catholic Legion of Decency at the time, I believe I didn’t sufficiently dramatize the erotic aspect of Humbert’s relationship with Lolita, and because his sexual obsession was only barely hinted at, many people guessed too quickly that Humbert was in love with Lolita. Whereas in the novel this comes as a discovery at the end, when she is no longer a nymphet but a dowdy, pregnant suburban housewife; and it’s this encounter, and his sudden realization of his love, that is one of the most poignant elements of the story. If I could do the film over again, I would have stressed the erotic component of their relationship with the same weight Nabokov did. But that is the only major area where I believe the film is susceptible to valid criticism.

—While Kubrick was preparing to cast the part of Lolita, he received odd letters from parents saying things like: “My daughter really is Lolita!” Almost 800 girls auditioned for the controversial role.

—On the censorship of Lolita:

Plenty of double entendres found their way into the shooting script, as Kubrick was able to keep the prying eyes of Hollywood away by shooting the film in London. He figured he’d be able to present the finished film to the censors as a fait accompli and not have to worry about script approval. To be safe, he hired consultant Martin Quigley, who had helped write the Hollywood Production Code in the first place, and who was close to the clerics in the Legion of Decency, to lobby both groups on behalf of “Lolita.” The Code Administration objected to some of the smirkier lines of dialogue and to the lengthy scene where the precocious Dolores seduces Humbert. So did the Legion, threatening the film with its “Condemned” rating, a commercial kiss of death. In response, Kubrick trimmed the offending lines and cut short the seduction scene with an earlier fade-to-black, thus earning Code approval and a milder “Separate” rating from the Legion. The posters advertising the film also claimed that it was only for adults 18 and over. (Indeed, at the New York premiere, star Sue Lyon, then 15, was denied admission.)

—Kubrick felt muzzled by censors and told Newsweek in a 1972 interview that if he had realized how severe the censorship was going to be, he “probably wouldn’t have made the film.”

—Celebrity photographer Bert Stern took the publicity photos of Lolita wearing heart-shaped sunglasses. But in the movie, Lolita wears cat-eye sunglasses.

—”The Edgar Allan Poe poem Humbert reads to Lolita is “Ulalume.” According to an ear-witness at a Poe recitation of the poem, the author pronounced the title as ‘You-la-loom.'”

—Recalling the pressure surrounding the casting and portrayal of Lolita, producer James Harris stated: “We knew we must make her a sex object — she [couldn’t] be childlike. If we made her a sex object, where everyone in the audience could understand why everyone would want to jump on her, and you make him attractive, it’s gonna work.”

—Novelist and screenwriter Calder Willingham(Paths of Glory) gave Kubrick a copy of Lolita and encouraged author Nabokov to sell rights to his books to Hollywood. Gillingham wrote the first drafts of Lolita before bowing out when Nabokov entered the picture, making his screenwriting debut.

—After Nabokov was asked to write the screenplay, he told Kubrick he previously had a “nocturnal illumination of diabolical origin” about the project. The writer had a dream that he was reading his own screenplay.

—James Mason occasionally stormed off the set, upset by his inability to match Sellers’ talent.

—Kubrick almost fired Shelley Winters (who played Charlotte Haze) several times. According to cinematographer Oswald Morris: “[She] was very difficult, wanting to do everything her own way. At one point Kubrick said to me, ‘I think the lady’s gonna have to go.”

—Charlotte and Lolita watch The Curse of Frankenstein (1957) during the drive-in scene. For part of the scene, Kubrick had a different soundtrack recorded to make the film seem scarier than it was.