"It's not what you don't know that gets you into trouble. It's what you know for sure that ain't so," says Mark Twain. And Tom Kelley, General Manager of IDEO, cites this famous quote as an example of why it's important for creative minds to continue to cultivate a dedication to continuous learning. He tells the story of retailer Best Buy, and tracks their huge investment and acquisition of a large CD retailer which they thought was a good idea - except for that their target market had stopped buying music and started downloading MP3's instead. The electronic retailer was overly confident in their knowledge of the market, and paid for their lack of learning with a billion dollars in lost revenue.