A pilot was showing his son the effects of headwinds and tailwinds over two trains. The pilot did not realize the lesson was fully learned until months later when he heard from a school psychologist who had been conducting an evaluation of his son.
Psychologist: What color is a banana?
Son: On the inside or the outside?
Psychologist: What is faster, a train or a plane?
Son: It depends on the headwinds.
