Once, as a child, I played sick to avoid a particular confrontation that I knew was going to take place at school. My plan was foolproof: Moan a little bit, wait for the thermometer to show up, and then fake a fever using my desklamp to inflate the reading. I may or may not have recently watched “Ferris Bueller’s Day Off.” In either case, I would have been more successful in my devious effort if I had followed his advice and...