As a teenager, Toby Keith witnessed the power of a song firsthand. He tells Esquire magazine that while visiting a friend's house to hear some tunes the guy had written, he noticed the girls in the room were swooning, even though Keith himself was unimpressed.

"I could tell they were just average songs. I'm wondering, What are these girls freaking out about?," he says. "The more I listened, the more I realized it was about the act of creation. The girls thought they could see into his heart and soul. So, I started writing songs."

Keith also reveals a little-known detail about one of his most popular songs.

"I wrote '[Courtesy of the] Red, White and Blue' in twenty minutes on the back of a fantasy-football computer printout," he says, adding, "It's amazing how much power there is in the phrase 'boot in your ass.'"

Look for the complete Toby Keith interview -- and an additional feature on country legend Charlie Daniels -- in Esquire magazine's January issue.