In the Seventh Arrondissement of Paris, there’s a perfect little restaurant that specializes in Burgundian food. I’ve been going there for 20 years, and nothing—the napkins, the menu, the stuffy bourgeois crowd—ever changes.

But on a recent visit, the dashing, snowy-haired gentleman at the neighboring table truly shocked me. “I’ll have the quenelles, poulet au vin jaune, a side of pommes vapeur, and, to drink, a Diet Coke,” he said, unwinding his foulard. “With ice.” The waiter didn’t even blink.