A father and son went fishing one day. After a couple hours out in the boat, the boy suddenly became curious about the world around him. He asked his father, "How does this boat float?"

The father thought for a moment, then replied, "I don't really know, son."

The boy returned to his contemplation, then turned back to his father, "How do fish breath underwater?"

Once again the father replied, "Don't really know, son."

A little later the boy asked his father, "Why is the sky blue?"

Again, the father replied. "Don't really know, son."

Worried he was going to annoy his father, he said, "Dad, do you mind me asking you all of these questions?"

"Of course not son. How else are you ever going to learn anything?" replied his father.