Skirt around them all you like, there’s no getting away from mum and dad. It’s something most artists learn the further they tread into a career. Sooner or later, the sleeves have to be rolled up and the dynamic that brought you into being needs to be placed under the microscope. That’s what Steven Spielberg found out after six decades of “hiding” from the story of his parents. The evergreen storyteller had always sprinkled breadcrumbs from his family table here and there in his films. They’re plain to see in the adult-child interplay of E.T. or Close Encounters of the...