Before you have kids, you fantasize a perfect being based on the choicest morsels of the parents’ body and soul: inshalla, my child will have Daddy’s button nose and Mummy’s indestructible teeth, his Calvinistic work ethic and her knack of being given jobs by friends, his talent at Angry Birds and her ability to sprint after a departing bus in platform heels while exceptionally drunk.What you don’t imagine, is a child made up of all the offcuts: Mummy’s enormous conk grafted onto Daddy’s bowling-ball bonce, his science-baffling foot diseases combined with her shedding toenails, his inability to find his own belongings mixed with her incendiary temper at losing things.