As a schoolboy at Eton, Boris Johnson discovered the gift that has been his lodestar ever since: an ability to make people laugh. According to his sister Rachel, “He was in a Molière play and he hadn’t bothered to learn his lines. So, he hid behind a pillar reading them out, which was obviously much funnier.” The performance was enhanced by letting the audience in on the gag: it is all only a game and, in the end, does anything about it really matter?  This knowing, winking, collusion between performer and audience has been the one constant in Johnson’s careers.…