There was this helicopter pilot whose job was to ferry VIP's from Seattle airport to downtown. One day he found himself with a passenger in a pea soup fog somewhere over downtown Seattle. No landmarks were visible and the passenger became panicky. The pilot said "Don't worry" and very gradually let the helicopter down until it was hovering opposite the window of a large, unidentifiable building.
The pilot motioned to a woman working in the building to roll down her window and asked
her "Where are we?"
The woman responded "You are in a helicopter."
The pilot immediately lifted the helicopter above the building tops, flew a mile and a half, let it down through the fog, and hit the landing pad dead center. The amazed and relieved passenger said "How on earth did you do that?" The pilot said: "It was simple. The information the woman gave me was precisely correct and totally useless. I knew that she had to be working at the Microsoft Customer Support Center."