I usually do most of the explaining. I studied geology and geography and worked as a national park ranger in lots of areas around the U.S., and drove across many many times. Makes looking down at all of those familiar places pretty interesting. There have been some "aha!" moments for people who asked the questions, but I don't remember any particular stories at the moment.

The strangest thing I saw (but I knew what it was) was right out of one of the Narnia books (Magician's Nephew?). Flying over the Llano Estacado (Texas), west of Amarillo at night after heavy thunderstorms had passed. We were in a clear sky, full moon, and below were hundreds of depressions filled with water that were all reflecting that bright moon back up an us. It was a singular experience!

SRS