This obsession makes “I Think You Should Leave” the perfect comedy for our overheated cultural moment. The 21st-century United States is, infamously, a preschool classroom of public argumentation. Our one true national pastime has become litigating the rules, at high volume, in good or neutral or very bad faith. “Norms,” a concept previously confined to psychology textbooks, has become a front-page concern. Donald Trump’s whole political existence seems like some kind of performance-art stunt about rule-breaking. The panics over “cancel culture” and the “woke mob” — these are symptoms of a fragmented society wondering if, in a time of flux, it still meaningfully shares social rules. Every time we wander out into the public square, we risk ending up screaming, or screamed at, red-faced, in tears.

“I Think You Should Leave” makes comedy, relentlessly, out of moments when the social rules break down. When things stick, grind and break.

Almost always, sketches start quietly. The show reproduces, with loving accuracy, our small-talk, our polite jokes — the way groups use humor to defuse social tensions. A woman, holding her friend’s new baby, says to her partner, teasingly: “Maybe we could have another.” To which he responds, with a nervous grin: “Uh, let’s talk about that later.” Men at a poker game trade jokes about their wives. (“Trust me, my wife has nothing to complain about — unless you’re talking about every little thing I’ve ever done!”)

A lot of “I.T.Y.S.L.” sketches seem to start with a little thought experiment: What would happen if someone took this throwaway joke literally and seriously? How would it warp social reality if these anodyne little pleasantries were actually brought center stage — if someone ignored all the rules we are supposed to intuitively understand?

This is the premise of one of the show’s best sketches, a sketch I’ve memorized so deeply I can hardly even see it anymore. A man at a party is allowed to hold a baby, which cries as soon as it nestles into his arms. “It’s not a big deal,” he says, good-naturedly. “I guess he just doesn’t like me.” That’s a classic, lukewarm, tension-defusing witticism, and everyone smiles politely. But Robinson has invented a guy who takes this absolutely seriously, who becomes obsessed with explaining to everyone, at the top of his lungs and at great length, precisely why the baby doesn’t like him — because it knows, somehow, that he “used to be a piece of [expletive].” Gradually, the man hijacks the entire party with obsessive explanations of all the many ways he used to be reprehensible — “slicked-back hair, white bathing suit, sloppy steaks, white couch.” And he insists, over and over, that “people can change.” The reasoning is absurd, and yet he is so sure and persistent and literal that it becomes a kind of social contagion. By the end of the party, everyone has come over to his side — including the baby, who smiles at him.