Suppose I show you some object and say, "This is a flurnitron. Isn't it perfect?" What would you answer?
That's right, you'd ask, "What does it do?" or more skeptically, "What is it supposed to do?" But in either case, you want to know its purpose, because you cannot tell whether something is good or bad until you know its purpose and how well it fulfills that purpose.
Thus, your first question about the flurnitron would not be, "How much electricity does it use?" or "Is it made of steel?" or the like. Until you know what it was designed to do, those questions are irrelevant. What we value in an object is not what it's made of or how it's powered--until we understand the relevance of those answers.
So, when we think about our own lives, before we can answer, "Am I a good person living a worthwhile life?" we have to determine the purpose for which we exist. For if everything exists to fulfill its purpose, we can evaluate everything based on the extent each thing fulfills its purpose.
If, as the marketers seem to imply, our purpose is to consume products and spend money, then many of us do that really well. If we have no purpose, then it doesn't matter what we do, and there is no estimation of fitness to purpose possible. But if we do have a purpose--to serve God who created us and to be his hands in serving his children--our fellow human beings--then we can adjust our lives to align ever more closely with that purpose. That purpose, to steal a few words from Shakespeare, "is the star to every wandering bark," providing a fixed focal point for our behavior.
Therefore, we can see that finding the best steak in town or memorizing the names of all the players on a favorite professional sports team or driving the fanciest car on the block are activities that do not really speak to our purpose. I myself am rather embarrassed to think of the highly tangential nature of many of my own pursuits. These comments, then, are addressed to me.