Humans are a strange breed. Forgetful. They grow accustomed to the wonders they live among so easily that they never really figure up the cost. A little time passes and the bright memories tarnish and are covered over with newer ones. And the men who picked up the check and maybe paid with their lives? Forgotten. For example, when you're sitting comfortably in the New York to San Francisco stratojet, and you take the trouble to look down at the lush verdure of the eastern slope of the Sierra Nev