" The next time you run into a question that you can only pretend to answer, go ahead and say “I don’t know”—and then follow up, certainly, with “but maybe I can find out.” And work as hard as you can to do that. You may be surprised by how receptive people are to your confession, especially when you come through with the real answer a day or a week later. "

― Steven D. Levitt , Think Like a Freak