Every single human being is creative and maximizing that creativity is critical to happiness and economic growth. Economic growth is driven by creativity, so if we want to increase it, we have to tap into the creativity of everyone. That's what makes me optimistic. For the first time in human history, the basic logic of our economy dictates that further economic development requires the further development and use of human creative capabilities. The great challenge of our time is to find ways to tap into every human's creativity.