Interesting question, isn't it? It's actually the title of a book I read years ago. The author pointed out that people spend their life seeking fulfillment in many things that turn out to be of little value. I shared with our graduating seniors this past Sunday that there are many things in life that will call to them: Prosperity, pleasure, position, fame, and education. While any of them are fine in moderation, none of them are worthy of being your life's purpose. Yet sadly many you know will spend their lifetime pursuing one or more of them only to find that, in the end, their achievement will not have brought them fulfillment in life.
The great King Solomon achieved all of them but concluded in Ecclesiastes 2:11, "When I surveyed all that my hands had done and what I had toiled to achieve, everything was meaningless, a chasing after the wind; nothing was gained under the sun." His advice to us, found a few pages later in chapter 12:1 is, "Remember your Creator in the days of your youth...."
Pursue prosperity, pleasure, etc and you will no doubt regret it. Seek after Jesus and you will never regret it!