Well, I am officially beat. Just got back from an elementary school. I did seven presentations today, for kids ranging from kindergarten up to fifth grade. The morning consisted of five straight 30-minute sessions with a five-minute break in between. The afternoon sessions were a bit longer, since I had older kids who can usually sit still for slightly more than two-point-seven nanoseconds. Not that I'm complaining. I love doing it. I'm just...tired. The challenging thing is repeating the exact same presentation five times in a row while trying to make it sound fresh for each group. I think I …