Satisifed, and yet not

Jeremiah Burroughs in The Rare Jewel of Christian Contentment:

You never learned the mystery of contentment unless it may be said of you that, just as you are the most contented man, so you are also the most unsatisfied man in the world. You will say, 'How is that?' A man who has learned the art of contentment is the most contented with any low condition that he has in the world, and yet he cannot be satisfied with the enjoyment of all the world.