In fact I was a man weighed down with disappointment, a man for whom things had not worked out the way he had once imagined, a quiet man, cautious in his life, timid when you came right down to it, though content enough to drift along through the little rituals of his day.
For GPS, this is an enormous issue because it turns out that the clocks on the satellites drift by almost 40, 000 nanoseconds per day relative to the clocks on the ground because they are high above the earth's surface (and therefore in a weaker gravitational field) and are moving fast relative to the ground.