One day, when the teacher walked to the blackboard, she noticed someone had written the word “penis” in tiny letters. She turned to the class, scanned the boys and girls, looking for the guilty face. Finding not a guilty face in the bunch, she quickly erased the blackboard and began her class. The next day, the teacher went into the classroom and noticed, in larger letters this time, the word “penis” written on the blackboard. Again, she looked around the classroom in vain for the culprit,...