Academic friends say their students answer calls during lectures. Lovers lolling on the public grass on a sunny day glare at you if you look at them, as if you have just walked into their living-room. People chat in the cinema during the film, and sometimes during the play. Air travellers on long-haul flights change into pyjamas in the lavatories. It's as if we now believe, in some spooky virtual way, that wherever we are, it's home.