Carrie Underwood is one cool customer. When she won American Idol, she went from college student to tv princess in a matter of weeks, and yet never seemed to get ruffled. She headlined her own tour this year, and looked completely comfortable last month co-hosting the CMA Awards. But Underwood told The Tennessean that she is actually just very good at hiding her nerves. "Usually before live TV performances are when it's the worst. About halfway through the song, those go away," she says. "There's a lot of adrenaline going through my body. Sometimes my left leg will shake uncontrollably if I am really nervous.... I feel like I'm like a dog when you scratch him." Underwood also revealed that learning to talk to the crowd between songs has been her biggest challenge. She compares it to trying to have a conversation with thousands of people. Underwood described a recent show in Arkansas, where a woman held up a poster with a picture of a soldier and the words "Our Dream Ended" during her performance of "Just a Dream." Underwood said she couldn't finish the song, and had to turn away from the crowd so she wouldn't cry.