The average age of a first time mum at London’s Chelsea and Westminster hospital is 37, a statistic that tells you everything you need to know about the choices supposedly affluent city dwellers are being forced to make in the capital. For the middle classes, the cost of living in London — the cost of getting by — long ago went past insane (£17,040: the cost per year of educating a four year-old child at Thomas’s school in Fulham, not including uniform). It’s the incredible price of property, of course, that’s been the engine driving this madness, ratcheting the pressure ever higher on Londoners who don’t own a home while making very wealthy, on paper at least, those who do.

For the last two decades and more, the capital’s property market to all intents and purposes has behaved like a giant Ponzi scheme played on a global scale. Money from all over the world has poured into London bricks, inflating values unrealistically in relation to wages, while the lavish bonuses paid to European bankers working in the City have also stoked momentum responsible for pushing up, for example, the average price of a London semi-detached house by 553 per cent between January 1995 and November 2017, from £133,820 to £873,603.

Over the same period, the average cost of a detached house in the capital went from £257,748 to £1,453,271.

At last, however, the party is over. London property prices, now still flailing cartoonishly in mid-air despite being well over the edge of a cliff, are at the start of what we can call, for want of a better term, a death plunge. Although the carnage is only just beginning in earnest, desperate homeowners looking to sell are already dropping asking prices by tens of thousands of pounds and more. They know the tide is going out quickly.

The reasons you would have to be clinically insane to buy property in London today are blessedly easy to understand. Describing a modern financial disaster normally requires some pretence of understanding, say, derivatives markets or the myriad immensely complex ways international banks package and trade debt. Not this time.