In a sermon broadcast on the BBC on Dec. 25, 1950, Msgr. Ronald Knox observed that “we make a holiday of Christmas only if we have the strength of mind to creep up the nursery stairs again, and pretend that we never came down them.” In my case, the stairs in question led, not to a nursery, but to the children’s bedroom I shared with my brother at 1 Regester Avenue in the Baltimore suburb of Rodgers Forge. And down the stairs we slid, Christmas morning, to discover what had arrived (or, as we later learned, what had been assembled, often with the aid of my grandfather Weigel) the night before. The day that followed was one unmitigated happiness; and from the distance of more than half a century, I still remember the sweet sadness of Christmas...