How do politicians switch off?

‘Like a sea beast fished up from the depths, or a diver too suddenly hoisted, my veins threatened to burst from the fall in pressure. I had great anxiety and no means of relieving it […] And then it was that the Muse of Painting came to my rescue – out of charity and out of chivalry.’ 

So said Churchill in 1915 after the disaster that was Gallipoli. Salvaged by the Muse, Churchill found solace from the pressures of political life in art. Last week, another sea beast emerged from the depths, consoled this time not by a Muse (he does, however, like to paint) but by the Sirens of the sea. To watch Boris Johnson plunge into the waters of Carbis Bay before a tense day with Monsieur Macron at the G7 is to gaze through the small aperture of a politician’s private life, offered up to the public briefly and tantalizingly before it snaps shut and the mask of office is restored.