There is a story of a prisoner in a Russian labor camp whose job it was to turn a heavy wheel attached to a wall.
For twenty-five years the prisoner worked at his backbreaking labor.
He assumed that this wheel must be attached to a mill on the other side of the wall; perhaps he was milling grain, or pumping water that irrigated many fields. In his mind’s eye he saw the plentiful crops and the sacks of milled grain feeding thousands of people.
After twenty-five years of hard labor, when he was about to be released, the prisoner asked to be shown the apparatus behind the prison wall.
There was nothing there! The wheel was just a wheel—all his “work” had served no useful purpose.
The man collapsed in a dead faint, absolutely devastated. His life’s work had been in vain.