I am invigilating an examination, the second this school year. This time I am in my own building; my office is not far. A colleague of mine brings me a cup of coffee at half time. He administers all the examinations in our building. Judging by his facility and ease, he must have been doing this for a decade or two. As he places the cup on my desk, he notices that I have not brought with me anything to do. “Feel free to get something to keep you busy,” he whispers and points in the direction of my office. This is against the rules, but I offer an alternative explanation of my idleness: “Time to think.” He smiles back as he starts to leave the classroom: “Oh, that’s dangerous!”