It’s still the same old story. Seventy-five years after it was released, Casablanca (1942) remains one of the world’s best-loved films and one of my favourite films of all time. The film is not just the best-loved, but best-remembered. Many cinephiles can quote large chunks of the dialogue by heart, and Casablanca has the most entries of any film in the American Film Institute’s 100 Greatest Movie Quotes of All Time list.

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Casablanca is a story of Rick Blaine, a cynical world-weary ex-patriate who runs a nightclub in Casablanca, Morocco during the early stages of WWII. Despite the pressure he constantly receives from the local authorities, Rick's cafe has become a kind of haven for refugees seeking to obtain illicit letters that will help them escape to America. But when Ilsa, a former lover of Rick's, and her husband, show up to his cafe one day, Rick faces a tough challenge which will bring up unforeseen complications, heartbreak and ultimately an excruciating decision to make.

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During the course of the film, Humphrey Bogart’s Rick says “Here’s looking at you, kid” to Ingrid Bergman’s Ilsa four times, and what was once a jovial toast becomes a poignant farewell. When Rick and Ilsa agree that they’ll “always have Paris” they’re saying that the memory of a happy romance will sustain them through the pain of separation. It remains one of the most quoted one liners of all time.

Others being: Ilsa: “Play it once, Sam, for old times’ sake.”: Play it Again, Sam. "As Time Goes By" is the song that was playing the last night that Rick and Ilsa saw one another. Rick has requested Sam never to play that song, but Ilsa is the one who asks to hear it. This is another example of the way Rick has allowed his happy memories of Paris to be tainted by Ilsa's abandonment, and that her re-appearance has forced him to face the nature of his pain.

Ilsa: "With the whole world crumbling, we picked this time to fall in love.": During a flashback sequence, Ilsa and Rick enjoy a warm and passionate affair in Paris. However, they are forced apart when the Nazis invade. This quote is representative of the state of their relationship, and the eventual reality that these two people, despite their feelings for one another, will never be together.

Rick: "Louis, this is the beginning of a beautiful friendship.": This famous last line of the film refers to Rick and Renault's decision to escape Casablanca for the Free French Garrisson in Brazzaville. Renault and Rick have a lot in common at the beginning of the film. They both live by a code of self-interest and self-preservation.

Quotations from Casablanca appear everywhere from TV adverts to other films, right up to recent releases Allied (2016) and Atomic Blonde (2017). The film has been parodied by everyone from the Marx Brothers to Bugs Bunny. Paul Anton Smith’s compilation film Have You Seen My Movie? (2016) splices together several scenes from other films in which characters watch the final scene. Karina Longworth’s unmissable Hollywood history podcast takes its title, You Must Remember This, from a line in ‘As Time Goes By’, and each episode is introduced by the haunting sound of Bergman humming the melody.

Woody Allen sampled the entire movie in a 1969 play, filmed by Herbert Ross in 1972, although the title – Play It Again, Sam – is famously a mangled misquotation of what Rick actually says to his pianist. Bryan Singer’s 1995 thriller The Usual Suspects took its title from one of Renault’s lines. Emma Stone’s Mia in La La Land (2016) is obsessed with the film, sleeping underneath a giant poster of Bergman and working opposite one of its key shooting locations – which suggests a grim prognosis for her fling with Ryan Gosling’s Sebastian.

I can watch the film over and over again, year after year, and it would never grow over-familiar. It plays like a favourite musical album; the more I know it, the more I like it. The black-and-white cinematography has not aged as colour would. The dialogue is so spare and cynical it will not grow old fashioned ever.