I thought I’d seen “Betty Blue” before. The title seemed vaguely familiar to me. So, for years I avoided the movie, convinced by the pouting girl on its cover that I’d seen it already. A standard piece of Hollywood dross, I told myself. Not even realising that the film was French and subtitled. But once the story started and threw us into the mix with its languid photography and that long, sweaty, obsessive sex scene that introduces the director’s cut, I was hooked.