We always know there is something up because of the helicopters. Living in central London, we have become used to the police circling overhead, as they did last week, when monitoring the students rioting in Millbank. They make a terrible noise.

It happened to be the evening when my wife and I were going out to celebrate an important wedding anniversary (which both of us had previously forgotten) at the discretely opulent Goring. As we ate our eggs Drumkilbo and venison, we felt we were living through the revolution scene in Dr Zhivago.

I had seen the protest stirring earlier in the day, when I passed a group of demonstrators, carrying placards. One of the slogans read ‘Wagner to win The X Factor’: not even I could think this was a reference to the composer of Parsifal. (Would Richard Wagner have been on the side of the students, or the authorities?)

When I went to Cambridge, the February 1970 Garden House riot (during which the hotel of that name was trashed) was still fresh in the memory. But by my time, agitprop was not what it had been: the cause wasn’t Vietnam, but that of the Nursery Action Group, demanding daycare for the children of mature students. The acronym of NAG said it all.