I suggest that while we're measuring everything else so carefully, we don't have a clue how to measure our success at living. The central purpose of life is to be happy. I'm not talking about being entertained or excited. When most of us say we're happy, what we're really saying is that things around us are going our way. That kind of happiness depends on circumstances and the actions of other people.
Real happiness comes from being responsible, feeling unconditionally loved, and loving others.
It's a sense of fulfillment and strength that fills the soul deeply. It's a profound peace that doesn't come and go with changing circumstances. It grows with struggle and doesn't vanish during inconvenience and pain. It's happiness that determines our success. We're easily fooled by excitement and entertainment, believing that with sufficient quantities of those we're happy.