Oprah has been answering this question since her very first O, The Oprah Magazine column in May 2000. In our November 2008 issue (our 101st!), authors, thinkers, artists, activists, and actors answered the call. But we want to hear your thoughts—what are your guiding truths? What message gets you through the day? As Oprah says, the power of the question is the power of sharing its answers.