We planned to be away last New Year’s weekend when our son, who follows the rock, jam-band Phish, had tickets for several shows during their annual Madison Square Garden winter tour. He and five of his Phish-loving out-of-town friends asked to stay in our Manhattan apartment during our absence. On that Friday afternoon one of the group offered to go down to the supermarket for groceries and my son asked him to also pick up a challah. “And tell them not to slice it.”, he...