IT'S A KIND of immortality, isn't it, to have one's youth frozen by achievement and lit by approval. Look at these faces: innocent of infirmity, blind to corruption, the eyes still pools of purity and purpose. Not one wrinkle of self-doubt, no furrows of anxiety, nobody saddlebagged by defeat. There's merely that otherworldly calmness, the comfort of one's gifts. It's so easy, to be young and bursting with brio, to simply stare down the years to come, as if anything--or rather everything--might be right around the corner. Look at these faces: Who would tell them otherwise?