> So far no one has, there must be a reason no one can. I am reminded of the story of two economists walking down the street. One spots a $20 bill on the side

> So far no one has, there must be a reason no one can. I am reminded of the story of two economists walking down the street. One spots a $20 bill on the sidewalk points it out to the other, who says "Don't be ridiculous, if there really were a $20 bill on the ground someone would have picked it up by now."