John Preskill (among others) in Physics Today:
By the summer of 1981, I had completed my PhD under Steve’s supervision and was starting a junior faculty position at Harvard. I knew that my parents, who were visiting, would enjoy meeting Steve and Louise, so we all had dinner together in my backyard. Realizing how much it would please my parents, Steve made some kind remarks about me during dinner. But the most memorable moment was when we were discussing how to make ice cream, and Steve expressed puzzlement over why one adds salt to the ice-cream maker. My Dad, who was not a scientist, helpfully suggested, “Isn’t it to lower the melting point of the ice, so the ice cream will be cold enough to solidify?” “Of course!” Steve replied, slapping his forehead. “I never understood that before. Thank you!” And for the rest of his life, my Dad would relish the time he gave the great Steven Weinberg a physics lesson.