In 1980 and 1981, the GLC (Greater London Council, headed by Ken Livingston, now London’s Mayor) put up posters all over the city. They gave them out to schools and churches and mosques, pasted them outside tube stations and near museums and shopping centres. The posters depicted a simplified map of greater London, with blue lines drawn to demonstrate which areas were at greatest risk from flooding, should the Thames ever spill its banks.

The map showed clearly which areas would remain safe - the high ground of Notting and Muswell Hills and Hampstead, for example - and which would be glugging under water when the time came - Pimlico, great swathes of Fulham, Chelsea and South London. The maps were entitled “What To Do If London Floods” to which some cheeky scamp had generally added “swim for it” or “the breaststroke”.

I studied the maps with fascination and awe, slightly peeved that in the event that Lonodn did flood, my home would be perfectly safe, and there would therefore be no possibility of climbing out of the top floor bedroom window into an inflatable dinghy, and paddling off to school - a fantasy which occupied a great deal of my thinking time, aged seven, because it was so potentially exciting.

Of course, in those days, I neither knew nor cared about structural damage, contents insurance and the special health perils of stagnant water. Probably a good thing, too. Kids shouldn’t have their fantastic fantasies intruded upon by harsh reality like insurance.

When the Thames flood barrier was opened in 1982, I was sad, because that meant we’d never see the city flooded.

I soon switched my attention to other disasters, though. In school, aged eight, nine and ten, they teach you an awful lot about the plague, the Great Fire of London and the Blitz. Of all of these, I became preoccupied with the Blitz: incredibly worried about the possibility of London being bombed.

Bear in mind that this was at a point when there was a lot of talk about nuclear weapons and what to do in the event of a nuclear attack (paint your windows white, do something inventive with a door up against a wall, and hide, as I recall). This was the eighties, the time of Thatcher and Reagan and When the Wind Blows.

Nuclear war was (and is!) petrifying. But the stories about the Blitz caused more worry to me. Why? Because the main bit of information that I carried away from my lessons about the bombing raids on London was that when the bombers came, most people were OK because they hid in the depths of the tube stations. Sorted.

Except that my local tube station was Ladbroke Grove, on the Metropolitan (now Hammersmith and City) Line. Above ground. The next nearest was Latimer Road. Above ground. Westbourne Park, Royal Oak, Goldhawk Road - all of them, above ground. Fuck. Where would we go? How would we stay safe?

The worry about where we would go in the event of bombing worried me for years, until I grew old enough to realise that the threat had receded, and that in the event of a nuclear blast in London, we’d all be buggered anyway.

I’ve recently started worrying again.