President Bush was visiting a classroom where a teacher was giving a lesson on blood circulation. Trying to make the lesson clearer, he said, “Now, children, if I stood on my head, the blood, as you know, would run to my face.”
“Yes, sir,” one of the girls said.
“Then why is it,” he continued, “that while I am standing upright the blood doesn’t run to my feet?”
“Because your feet aren’t empty,” replied a boy in the back of the room.