Zuckerberg, the social network's cofounder and CEO, is incredibly awkward in interviews. But he actually studied psychology at Harvard before he dropped out to start Facebook. And an intense curiosity about what people are thinking pervades his work. His obsession with Twitter, with its real-time sampling of users' mental mundanities, led to his push to turn Facebook into a Twitter-like real-time monitor of people's thoughts. And now he's going on Oprah this afternoon. What better place than her couch to talk about what America is feeling? What's on our mind is what's on Zuckerberg's mind.