“My overwhelming impression of Boris was a clever person pretending to be stupid, unlike most people who are stupid people pretending to be clever,” said Rooney. “Getting him to do work that he didn’t want to do was difficult. He was absolutely uninterested in detail, so you had to check his copy carefully as it would be full of minor mistakes. The big-picture stuff he would get correct, but the detail was often sketchy at best. Names and dates would be wrong. You got the impression that he was simply remembering it, rather than researching.”

Rooney stressed that his experience of Johnson was “a long time ago… and we all change,” but his description seems to be a near-exact match for much more recent experiences, and in jobs where Johnson’s lack of care for details resulted in worse problems than a stray name or date here or there. One current British government minister who worked with Johnson when he was foreign secretary told The Daily Beast that so disinterested was Johnson in detail that his civil servants eventually lost their patience with him and decided to subject him to a secret test.

“His civil servants prepared comprehensive briefing packs which were rarely used,” said the minister. “They began to insert odd material in the latter chapters to see if he ever raised any queries or concerns, but they remained untroubled by BoJo.”