Meryl Streep, as Karin Blixen, throatily reminisced: "I had a fahm in Africah". I can go one better; in Africa, I had a garage floor made partly of the Berlin Wall.

At the end of a Cape Town day, the Continental tyres of my BMW rolled into place on the concrete in which chips of Wall were embedded. It was satisfying symbolism, and a riff on the old saying that East Germany produced the Trabant and West Germany the Mercedes; and another monument to the fact that, among generations of German economists, Herr Marx was a flop.

How did chips of the Wall end up in the mix of my garage floor? In 1993, I had bought the house with someone who had been present on the pavement as the hammers fell, and who had returned from Germany with a plastic bag of concrete keepsakes. These were the real thing, not knockoffs from a building site hawked by some chancer who, many generations before, would have been flogging fragments of the True Cross.

(It frequently is said that were all the fragments of the True Cross reassembled, there would be multiple exemplars of that instrument of execution; I suspect that were all the supposed chips and chunks of Wall glued back together, it would be visible from space.)

So, much of that plastic bag was mixed into the garage floor, adding a mosaic touch from a few fragments of colour, red and green and yellow, where graffiti had been sprayed on the Western side; and every morning and every evening, the wheels rolled over them.

In 2001, I sold the house, and on handing over the keys, told the story to the new owner, earning only an uninterested "oh". Had I had a thin chisel, and the time…