I walked briskly to the Spear’s Book Awards lunch at the Criterion Restaurant on Piccadilly Circus. Walking briskly, even if you’ve gone, initially, to the wrong venue, cannot be recommended in this heat. But the immense Byzantine space of the restaurant had a calming, if not an immediately cooling, effect. Walls of marble rise up into a glittering mosaic vault.

In 1900, there was no more bustling rendezvous than the Criterion, its Long Bar staffed by a well-drilled army of barmaids. Whistler would lounge away the afternoon there; even Ghandi visited as a young lawyer. But, oh, can’t they modify the lighting, still as glaring as in the gaslight era? It’s rather like lunching in a swimming pool.

I passed by the Criterion again on Saturday morning, taking my nine-year-old son Charlie to a recording studio; a friend had offered him £20 to be Third Pig in an iPad app about fairy tales. (‘That’s Two Zero, Dad. I don’t get out of bed for less.’)

A bendy bus having blocked the end of Piccadilly on a semi-permanent basis, we had to abandon the car. As I sauntered back through the Mediterranean warmth, past a group of Italians, I felt I’d gone on holiday without leaving home. Was it because I was wearing shorts?