Suppose you want to go to L.A. from Syracuse. Well, everyone knows that you can't go anywhere directly from Syracuse, so to go to LA you'd have to stop in, say, Chicago. But you can't go anywhere directly from Syracuse, so to fly to Chicago you'd have to stop in, say Cleveland. But you can't go anywhere directly from Syracuse, so to fly to Cleveland, you'd have to stop in, say, Pittsburgh. But you can't go anywhere directly from Syracuse, so to fly to Pittsburgh, you'd have to stop in, say, Philadelphia. Thus because flying between Syracuse and any other airport means that you'll have to stop at another airport in between, you can never get to your destination.