There is a legend of a man who was lost in the desert, dying of thirst. He
stumbled on until he came to an abandoned house. Outside the dilapidated,
windowless, weather–beaten, deserted shack was a pump. He stumbled forward and
began pumping furiously, but no water came from the well. Then he noticed a
small jug with a cork at the top and a note written on the side: "You have to
prime the pump with water, my friend. P.S. And fill the jug again before you
leave." He pulled out a cork and saw that the jug was full of water.