Some people are like the ship captain who, the story goes, saw what
looked like the lights of another ship heading toward him one night at
sea. He had his signalman blink to the other ship: "Change your course
10 degrees south." The prompt reply was "Change your course 10 degrees
north."

The captain answered "I am the captain. Change your course south!"; to
which the reply was, "I am a seaman first class. Change your course
north."

This infuriated the captain, so he signaled back: "I am a battleship.
Change your course south." The reply came back, "I am a lighthouse.
Change course north."