“I was just wondering what makes dames like you so dizzy.” So queries Peter (Clark Gable), a crafty if unemployed newspaper writer, in It Happened One Night. He’s speaking to Ellie (Claudette Colbert), the missing heiress and potential story serving as his traveling companion, and he doesn’t get a definitive answer.

For that matter, Ellie isn’t particularly dizzy on the scale of screwball dames of the 1930s. She’s a little spoiled, sure, not especially wise to the ways of waiting in line with the common folk, and by her own admittance never before alone with a man. But within those parameters, she’s relatively levelheaded and frequently resourceful – she knows her way around hitchhiking, anyway – and Peter’s question seems especially rhetorical. Future would-be Gables asking future spoiled-but-smart heiresses the same question would have an easier answer: they probably derive their particular dizziness from It Happened One Night itself, a romantic comedy that’s now been influencing other movies for 90 years since its initial release in February 1934.

You wouldn’t necessarily know it from contemporary romcom discourse, which tends to revolve around When Harry Met Sally. Realistically, that’s probably the right call; there are probably a nonzero number of romantic comedy fans for whom that movie is the oldest they’ve ever seen. (The situation is probably exacerbated by the sheer number of “all-time greatest romcoms” lists that refuse to acknowledge any movies made before that one’s 1989 release.) Frank Capra’s It Happened One Night might feel remote to that audience, with its contemporaneous Depression-era setting and its early-screwball pacing. (As thrillers and action pictures have gained in velocity over the past century, at least on an editing level, romcoms may be the genre that has slowed down the most, at least in terms of verbiage.) The next major anniversary it celebrates will be its centennial.

It’s also one of those movies with plot mechanics so familiar that it may be hard to see them with fresh eyes after nearly 100 years. Colbert’s Ellie runs away from her wealthy father, protesting his insistence that she annul her recent elopement. She crosses paths with Gable’s Peter, who agrees to help her reunite with her husband in exchange for an exclusive on her story. The pair bickers and banters their way from Florida to New York City, through a variety of ramshackle travel arrangements, and fall in love along the way.

The sheer volume of cinema inspired by Capra’s movie, whether directly or indirectly, is appropriately dizzying. There are the unofficial remakes, like The Sure Thing with John Cusack, or comedies that borrow the multi-vehicle-road-trip structure for more platonic means, like Planes, Trains and Automobiles. Some famous moments feel called forward from It Happened One Night regardless of intent: a bus-passenger singalong (like in Almost Famous), or a bride speeding away from her wedding at the last minute (like in The Graduate, where the postscript ennui plays even better if you know its worry-free ancestor). An exchange between Gable and a bus driver who won’t stop saying “Oh yeah?” was purloined by the high-school thriller Brick, despite taking inspiration from noir, rather than screwball. Even as titanic a figure as Bugs Bunny nicked from this movie; his trademark carrot-munching came from an imitation of Gable’s quirky (if decidedly health-forward) habit here. That the movie made a clean sweep at the Academy awards – going five-for-five by winning best picture, best director, best screenplay, best actor and best actress – is the rare Oscar decision that seems prescient, rather than dated.

Of course, you can’t be talked into loving a romantic comedy any more than you can be talked into a real-life romance, and it’s not the genre-defining influence of It Happened One Night that makes it such a great movie, anyway. It’s the opposite: the influence derives from how great it is – and how easy Capra and his stars make it look. The hitchhiking scene where Colbert gets a car to screech to a halt with a single leg is probably the most famous image and laugh, and if there are plenty of equally big laughs throughout, it’s also worth remembering how many other memorable images Capra makes out of a story that really only has two major characters. When Peter and Ellie first share a hotel room, with a makeshift “walls of Jericho” blanket hung up on a string to give each other privacy, the rain streaking their darkened windows looks silvery and otherworldly, as the characters begin to look more vulnerable in their separated silhouettes. There’s a similar effect later, when the pair move through the woods, dusky light sparkling up the nearby river as their relationship grows more intimate (though not quite physical). Then later still, another motel scene where Ellie makes a sincere confession of her love and Peter rebuffs her has starker, whiter lighting, playing up the discomfort. The black-and-white cinematography by Joseph Walker (who also shot His Girl Friday, The Awful Truth and It’s a Wonderful Life, among many others) is a reminder of how little some romcoms have to offer aesthetically, beyond the beauty of their stars.

Not that It Happened One Night is a slouch in that department: Gable and Colbert are beautiful, to be sure, but it’s surprising how much raw emotion they’re able to slip in between the banter. Watching the movie again, I was struck by how angry Gable gets in the final stretch, when it seems as if his new beloved has returned to her first husband. His furious disappointment played neither entirely comic nor fully melodramatic; it feels like the honest lashing out of a man who thought things would break in his favor, especially when contrasted with his merrily confident, hoarse-voiced telling off of his about-to-be-former employer in his first scene.

So it’s not just a question of this movie calling firsties – which it probably can’t anyway, as there were plenty of comedic romances that preceded it, nevermind other road-trip pictures or fast-talking journalists. Rather than inventing the romcom, it crystallizes so much about both the heightened genre and the real-life heart-zings it’s based on: the way that love rationalizes capricious decisions (and makes past decisions look more capricious), or how unacknowledged yearning from opposite sides of a makeshift wall can feel more intense than a traditional clinch. These are all emotions that can be, and have been, codified into screenwriters’ rituals, sometimes even with characters yammering about them along the way. It Happened One Night uses the emerging rhythms of screwball comedy to keep them honest; even its self-references feel confessional. It’s fitting, then, that the movie bookends Peter’s question about dizzy dames with an indirect answer of his own, when he punctuates his angry confession of love for Ellie: “But don’t hold that against me; I’m a little screwy myself!”