From Chapter Two:
It may be said of one who is contented in a Christian way that he is the most contented man in the world, and yet the most unsatisfied man in the world; these two together must needs be mysterious. I say, a contented man, just as he is the most contented, so he is the most unsatisfied man in the world. (pg. 42)
This is a "mystery" that the world will never understand. The believer should be content with the rudest of circumstances, yet not be satisfied with all of the riches of the planet. A Christian should be content with the barest essentials of life, and recognize that even if he had all of the wealth, all of the power, all of the prestige, and all of the fame of this world that none of these are able to satisfy the soul.
Only Christ can satisfy the child of God. At the same time, he or she will be content with whatever state God places them into. I pray that while this may prove mysterious to the world that it will be perfectly natural for you.