"You remember that Christmas when they got ill?" Mum says presently. "The year they were about two and three? Remember? And got poo all over their Christmas stockings, and it was everywhere, and we said, "It has to get easier than this"?" "I remember." "We were cleaning it all up and we kept saying to each other, "When they get older, it'll get easier." Remember?" "I do." Dad looks fondly at her. " Well bring back the poo." Mum begins to laugh, a bit hysterically. "I would do anything for a bit of poo right now." "I dream of poo," says Dad firmly, and Mum laughs even more, till she's wiping tears from her eyes."