As his fans multiply by the minute thanks to the growing American success of Ang Lee's kung-fu epic "Crouching Tiger, Hidden Dragon," Chow Yun-Fat, 45, said his secret to looking young is really quite simple. "You see," he said at a Hong Kong press conference this week, "I am very stupid. I don't understand or talk well. I take it easy every day. I am like an idiot. Be like this every day, and then you'll look young."