Ultimately though, it wasn’t so much the evolving porn industry as the changes wrought by time on Theroux himself that were the memorable features of this documentary. Followers of his work will have noted the shift away from crank-baiting and celebrity-seducing towards more serious subjects in recent times. Two films shown earlier this year about the treatment of autism and dementia in America were insightful, thoughtful pieces that shone a probing light not just on sufferers of mental illness but those tasked with caring for them, too. Here the contrast with his impish former self in clips from the earlier film was all too clear to see. Fifteen years on he didn’t seem quite so keen to brush over moral ambiguities for the sake of a joke.