The central events of On Chesil Beach – the tragic breakdown of a young couple’s love – are set just before the year Philip Larkin thought sexual intercourse began, “Between the end of the Chatterley ban / And the Beatles’ first LP”. The early 1960s, yet to start swinging, was still a time of ignorance and terror for English innocents approaching their wedding night. It certainly is for the unlucky protagonists of Ian McEwan’s 2007 novel, adapted for the screen by the author and directed by Dominic Cooke.