Book excerpt: FACES OF CHRISTMAS PAST is an engaging, middle-aged look at the perils of Christmas, our own self-imposed burdens of ritual duty (like the newsy Christmas Xerox), and the more unsettling fact that successive Christmases, more even than New Year's, mark the passing of our life from childhood to death. "Old Christmas card photos show us how we've aged," says author Bill Holm, "reminding us that, though time may curve in Einstein's physics, in our small life it is a straight line to white hair and bifocals."