The 1975 drama, one of the only films to ever receive the big five Oscars, remains a touchstone of American cinema with a resonant message of resisting conformity

A movie winning the big five Academy Awards – best picture along with honoring the lead actor and actress, writing and directing – happens so rarely that there’s not much use in examining the three movies that have pulled it off for common ground. But among It Happened One Night, One Flew Over the Cuckoo’s Nest, and The Silence of the Lambs, it may be Cuckoo’s Nest, released 50 years ago on Wednesday, that feels like the unlikeliest across-the-board triumph. It Happened One Night and The Silence of the Lambs both belong to rarely awarded genres (romantic comedy and horror, respectively), which makes their big wins unusual but also clearcut: here is an example of the best this type of movie has to offer. Cuckoo’s Nest, meanwhile, is potentially much thornier. It’s a comedy-drama made at least in part as allegory – an anti-conformity story of fomenting 1960s social rebellion, disguised as a movie about lovable patients at a mental health facility.

The Ken Kesey novel that the movie is based on was published in 1962, chronicling some of what Kesey saw as a hospital orderly and anticipating some of the coming pushback against postwar American conformity. The major change in Miloš Forman’s film is to shift the narrative away from Chief (Will Sampson), a towering Native American who presents himself as deaf and mute. Chief narrates the book, while the movie hews closer to the perspective of RP McMurphy (Jack Nicholson), who enters the facility having faked mental illness in the hopes that he can avoid serving out a prison work-camp sentence. Though the doctors don’t seem entirely convinced by his ruse, his behavior is apparently erratic enough for him to stay at least a little while. His attempts to bring more individualism and fun to his cohabitants runs afoul of Nurse Ratched (Louise Fletcher), who exercises tight control over the ward.