Chapter 16, Part 4B - Chuang Tzu

When the men of ancient times spoke of the fulfillment of ambition, they did not mean fine carriages and caps. They meant simply that joy was so complete that it could not be made greater.

Nowadays, however, when men speak of the fulfillment of ambition, they mean fine carriages and caps. But carriages and caps affect the body alone, not the inborn nature and fate. Such things from time to time may happen to come your way. When they come, you cannot keep them from arriving, but when they depart you cannot stop them from going. Therefore carriages and caps are no excuse for becoming puffed up with pride, and hardship and poverty are no excuse for fawning on the vulgar. You should find the same joy in one condition as in the other and thereby be free of care, that is all.

But now, when the things that happened along take their leave, you cease to be joyful. From this point of view, though you have joy, it will always be fated for destruction. Therefore it is said, Those who destroy themselves in things and lose their inborn nature in the vulgar may be called the upside-down people.
~ Burton Watson translation via Terebess Asia Online ~

Go here to read the introductory post to the chapters of the Book of Chuang Tzu.