A former ambassador to China and potential 2012 GOP candidate on the power of optimism:

Remember others. The greatest exercise for the human heart isn't jogging or aerobics or weight lifting – it's reaching down and lifting another up. Find a cause larger than yourself, then speak out and take action. Never let it be said that you were too timid or too weak to stand by your cause. Learn what it feels like to give 100 percent to others. It’ll change your life.