Delan Bruce at Techer:
With the passage of five decades, Leighton is understandably fuzzy about some of the details. But he believes he put what’s now known as “the restaurant problem” to Feynman, not at Indra, but later, at the physicist’s beach house in Baja California, Mexico, as the two were working together on the biography in the early ’80s. “Feynman said this in a lot of cases: The first thing you’ve got to do is clearly define what you’re trying to do,” Leighton remembers. In the case of the restaurant dilemma, he says, “I didn’t define it clearly—I still haven’t even today—I was just trying to describe my behavior. But Feynman defined the problem in a way that suited him and was solvable.”
Feynman constantly made notes, mathematical scribbles, doodles. He, of course, lends his name to Feynman diagrams, simple schematics he invented that depict patterns defining the interplay of light and matter. That night, as Leighton wondered when to order his favorite ginger chicken or try another dish, Feynman got to work, jotting down a formula in ragged cursive and drawing curious figures.
More here.