The happiness that material enjoyment brings is limited. Yet what we want is unlimited. How is it possible to fill an infinite space with something which has a limit? Certainly not in this lifetime! Our lifespan is no more than several decades, but even if we lived billions of years, we would still fall short of satisfying ever-growing greed. In fact, the longer we live, the greater our desire and the suffering that follows. Thus, the Buddha admonished us to keep our desire in check in order to gain true happiness; if we are always chasing after material things, we will never find real happiness.
Excerpt from Luminous Wisdom Book Series: The Paper Tiger ~ The Tibetan Buddhist View on Happiness