During a class, a number of students were amused when they thought I had made an obscene gesture while pointing to something overhead. I hadn't, but...

During a class, a number of students were amused when they thought I had made an obscene gesture while pointing to something overhead. I hadn't, but it reminded me of a story. In spring 2000, I was taking a taxi from a conference center in rural Bavaria, Germany, to the Munich airport.