When I was growing up, they were already a receding feature of the urban landscape: small-scale estates packed with one-storey houses and gardens that invariably burst with colour at almost any time of year. Many of the residents loved them dearly, as became apparent from the protests that erupted when the time came – 30, 40, even 50, years on – to replace what had been emergency housing, often built by German prisoners, and designed for a life of just five to 10 years.
Not everyone who lived in prefabs was enthusiastic. When one of the last such estates, in south-east London, was finally scheduled for demolition last year, a majority of residents wanted to leave, complaining of cramped conditions, the damp, poor insulation and primitive plumbing.
But the vote was not overwhelming, and what people liked about prefabs was that they were convenient; they had private space and gardens, and you didn't have to climb staircases or depend on an unreliable lift to reach your front door. For many, the high-rise estates that generally succeeded them were a step back in what might be called liveability.
Those prefabs have often come to my mind in recent weeks, as new construction sites have sprung up all over London. They don't come with mountains of rubble and dust-storms and fleets of heavy-duty lorries. They don't fester unfinished for months on end. They are fresh, clean and modern-looking. And when the wraps are taken off, what emerges is not by and large a monster of brick, glass and concrete, but light and elegant structures suited to their purpose as showcases. They may be temporary, but they are reasonably insulated against the elements and they have exemplary plumbing.
They are the pavilions that are being built by foreign governments and sports organisations to promote their presence during the London Games. Some are free-standing in the parks. Others are adjuncts to existing buildings. And all will doubtless be gone by mid-September. But the parallel between these structures and the post-war prefabs of old suggests that building homes for a growing and underhoused population need not be the ponderous undertaking it so often is in Britain. We appear to be rather good at designing and building prefabs for other purposes, so why can't some of this expertise be applied to everyday housing? You wouldn't want it in the Royal Parks, but there are plenty of empty brownfield sites in most cities, and high-tech prefabs must be a million times better than the garages and sheds that are turning into illegal shantytowns in parts of London.
We have a housing shortage. We have the know-how. When the Olympic caravan has moved on, let's put the two together.
The film that shows the pedalo's moment is here
There is one quality that Beijing did not have, nor Los Angeles nor Moscow, nor Sydney – all of which take themselves and their sport with unremitting seriousness. What London is already supplying in spades is a self-deprecatory irony – typified in the initial proposal to stage beach volleyball on Horseguards Parade.
All right, so the parade ground has now been largely subsumed by something awfully like a proper stadium, but the venerable backdrop is still there.
And for those who decide to turn their back on the actual sport, or take a temporary time-out, well, there's a veritable social history of Britain to be found in the theatre listings – social history that has almost nothing of national self-aggrandisement.
If you want the inspirational, you can start with Chariots of Fire. But you can go on to Billy Elliot (bitter-sweet), then to that cringe-making Mike Leigh drama Abigail's Party, and thence to Yes, Prime Minister at the Trafalgar Studios. If you still haven't got the message that there's an awful lot wrong with Britain to smile about, you could worse than drop into the cinema to see Swandown.
Two guys take the slow route, by swan pedalo, from Hastings to London. Their banter along the way includes comments about how a pedalo event would make for a slower, less competitive Olympics (positive, they seem to think) and how a spell of shared pedalling might do for the Israeli-Palestinian peace processes around the world.
The film is a gently pastoral idyll of a certain time and place. But I predict with complete confidence that by the autumn, the swan pedalo will be the must-have conveyance for any self- respecting British water park.