A few months ago I was accosted in a pub near King's Cross, in central London, by a drunk spoiling for a fight. Instead of trying to reason with someone unreasonable, I alerted one of the bartenders that trouble was ahead. My warning came too late. As soon as the drunk saw me talking to the bartender, he lunged at me, shouting “You! You!,” as if somehow I had betrayed the trust of this perfect stranger. He threw me against the wall, my pint glass shattering on the floor as I fell backward. And then he started to choke me. (For a drunk, his grip was surprisingly strong.) I couldn't tell you how much time elapsed—it felt like a long time, but was probably only a minute or so—before some of the other customers finally overpowered him.