I was walking the other night along a riverside promenade in the middle of the city of Melbourne, Australia, where street artists, on hands and knees, draw large chalk or crayon versions of Renaissance masterpieces on the pavement. I saw ahead of me a group of drunken young men who were waylaying passers-by and forcing them to admire and contribute to the retirement plan of an embarrassed artist. So I walked a bit faster and studiously avoided eye contact.
As I slipped past I heard one of the men say to one of the others who was going after me: "Leave him. He's on a mission."