Your pain giant may have been stalking you for months, years, or decades. Or he may have appeared in the flash of an exploding IED or in the crash of a car accident. Or he may have entered your life during the sudden onset of an illness.Suddenly, he's there. Maybe you don't realize right away how big he is. Then you look up and he's blocking out the sun.You look at your armament and all you have is a sling and a handful of pebbles. And your legs turn...