Lately I am often approached by unfamiliar ten-year-olds who have a singular purpose. I recognize their expression every time; it begins with a friendly smile, followed by a look of cunning, then a question: “Can I tell you a riddle?” “Okay, what’s your riddle?” I reply. And out comes the challenge: “What has four eyes but cannot see?” or “What has a mouth but doesn’t eat, a bed but doesn’t sleep, and runs but never walks?” Or perhaps it’s this one: “What does the poor have, the rich lack, and if you eat it you’ll die?” It all began during my recent book tour. At the first school event, I threw in a few riddles because there are riddles in my novel. I really didn’t expect much of a reaction, but the enthusiasm from students was obvious. Kids love riddles. Faced with this eureka moment, I suggested a riddle-making session,…