What is it that drives some people to embrace extreme risks, while the rest of us run to the safety of the sidelines? Lester Keller, a longtime coach and sports psychology coordinator for the U.S. Ski and Snowboard Association, says that not everyone has the mental character to excel in dangerous pursuits. He notes that most of us reach a point that limits our appetite for extreme risk and, as a result, our ability to perform well in dangerous conditions. But others have a much higher tolerance for risk. Take the example of Daron Rahlves, a top U.S. downhill ski racer. "The high element of risk makes you feel alive, tests what you are made of and how far you can take yourself," Rahlves said in a previous interview with U.S. Ski Team staff. "I'm not looking for danger. I'm in it for the challenge, my heart thumping as I finish, the feeling of being alive," he said. "I definitely get scared on some of the courses. It just makes me fight more... That's when I do best.