Some years ago, while on a trip back to the UK, I was walking with a friend through an ordinary English town. It was late, and the pubs were disgorging their inebriated clientele onto the streets. As is routine with me I dialed up my awareness and adjusted our path so as to stay reasonably clear of where people were clustering. My friend, a lovely man with a standard middle-class occupation, was talking happily about his most recent trip to India…