Many years ago, in a former life, I taught high school biology. The first day, I told my students that they could use their textbooks or any book to take any test that I would I give. They were surprised, and most thought that class would be very easy despite my explanations that it would not be. They were surprised again when they found that it was not as easy as they thought. This was because I asked them to think and reason with the information at hand.