A man is flying in a hot air ballon and realises that he is lost. He reduces height and spots a man down below. Lowering the balloon further he shouts out, "Excuse me, can you help me? I promised my friend that I would meet him half an hour ago, but I don't know where I am."

The man below says, "You are in a hot air balloon, hovering approximately 30 feet above this field. You are between 40 and 42 degrees N. latitude, and betwen 58 and 60 degrees W. longitude."

"You must be an engineer", says the balloonist.

"I am, how did you know?"

"Well, everything you have told me is technically correct, but I have no idea what to make of your information, and the fact is I am still lost."

"Well, you don't know where you are, or where you are going You have made a promise which you have no idea how to keep and you expect me to solve your problem. The fact is that you are in exactly the same position as you were in before we me, but now somehow it is my fault."