Three of my former students were in town last week and I had lunch with each of them. Meeting with them and hearing what they had learned in my class was very gratifying.

On Wednesday, I had lunch with one student, whose name I’ve not sought permission to mention. Because he was in a hurry to get back to a special class he was taking, I suggested we go to Costco and each have a hot dog. Big spender that I am, I offered to pay. He insisted on paying, saying that he wanted to convince me that, contrary to what I taught in class the first day, there is such a thing as a free lunch.

On Thursday, I went to lunch with Nuno Pires, a Marine officer who had taken my energy economics class in the spring of 2012 when it was first offered. He brought along a friend whom he and his family were staying with while in town and started systematically laying out to his friend some of the lessons he learned: why we don’t need to go to war for oil and how CAFE kills being the highlights. It was fun to sit there and watch him explain the reasoning clearly to his friend. Also gratifying is that when he laid out how CAFE had killed the station wagon, he got the reasoning right without remembering that I had written the article he was laying out. I like it when people remember what’s important without remembering who said it, although I do like them to remember the basic ideas associated with Adam Smith, Friedrich Hayek, John Maynard Keynes, Ronald Coase, and Milton Friedman

On Friday, I went to lunch with Eric Cheney, whom I hadn’t seen in the 13 years since I taught him. When I had run into him in the hallway earlier, he said that when he looks at his transcript, he sees A, A, A, A, B+, A, A, A, etc. and that the B+ is the grade I gave him in a course in which he learned the most. I asked him if that upset him and he laughed and said “Not at all.” “Notice,” he said, “that you’re the one professor I had here whom I wanted to look up.”