They say there's nothing new under the sun and, as usual, they are pretty much on the money.
Fashions, trends, fads, waves, movements come and go. Then the wheel turns and they come around again. No matter how silly, unsightly or impractical a thing is - flared trousers, mullet haircuts, post-structural theory - it will eventually seep back into the culture, albeit altered.
Yes, I'm afraid so: give it a decade or three and young men will once again be growing their beards and fringes and trying to look like an English novelist circa 1925, without the tuberculosis of course.
But if there's one thing I didn't expect to make a comeback, it's socialism of the "up the workers, squeeze the rich, if it moves, nationalise it" variety. Yet if the polls are to be believed - and they're all saying pretty much the same - Jeremy Corbyn is about to become the leader of the British Labour Party and thus Leader of Her Majesty's Most Loyal Opposition.
Corbyn entered Parliament after the 1983 election that put paid to the aspirations of Michael Foot, the last unreconstructed socialist to lead Labour. Often accused of not having had a new idea in his adult life, Corbyn is running on a platform and espousing a world view bearing a striking similarity to Foot's: pro-union, pro-state ownership and economic interventionism, pro-higher taxes; anti-austerity, anti-business, anti-American.
(Labour's 1983 manifesto was described as "the longest suicide note in history". The party won its lowest share of the vote since 1918.)
The comparison peters out about there: Foot, a distinguished journalist and biographer, was regarded as one of the great British parliamentarians of the 20th century and was admired across the political spectrum. Corbyn is a former trade union official who transitioned into politics via local government.
Corbyn has so little support among fellow Labour MPs that a third of those who nominated him for the leadership contest made it clear they had no intention of voting for him: they just wanted to ensure all sections of the party had a runner in the race.
He is bearded (a five-time winner of Parliamentary Beard of the Year), teetotal, vegetarian and doesn't drive. If a modern-day Dr Frankenstein set out to create a thing that personified everything Sir Bob Jones loathes about the human race, that thing would be Jeremy Corbyn who, naturally, is a feminist as well.
Indeed, if there's a positive to Corbyn's stunning rise, it's that he's the absolute antithesis of the carefully groomed and packaged identikit candidate: he's old-fashioned, long-winded, lacking charisma and not remotely telegenic.
Former British Prime Minister Tony Blair, who personifies everything Corbyn's supporters loathe about mainstream consensus politics, sees him as Britain's equivalent of Donald Trump, preaching a populism "that doesn't alter reality, but provides a refuge from it".
The comparison is valid inasmuch as both Trump and Corbyn offer the chimera of silver-bullet solutions to complicated problems. And neither is wrong about everything: probably because he's loaded, Trump's the only Republican presidential candidate who advocates campaign finance reform; Corbyn talks sense when questioning the advisability of Nato's eastward expansion.
But it's unfair on Corbyn in that, whatever else he may be, he's an idealist; you can question his grasp of the way the world works, but not his good intentions. Whereas Trump is a snake-oil salesman with a penchant for demagoguery and an ego like the Goodyear blimp.
So what's behind Corbyn's surge? Probably the fact that many of his supporters are too young to remember his policies have been tried before and didn't work. They don't know that, in practice, "empowering the trade unions" means giving a handful of union leaders a licence to hold the public to ransom and engage in economic sabotage. They're not aware that when the state ran the railway system it was even worse.
They're also disturbed by the growing inequality and unfairness that blight most Western societies: not only do the rich get richer, they often get bailed out by the taxpayer when they screw up; meanwhile life on Struggle Street doesn't improve.
I don't think Corbyn's programme will work. I strongly suspect it will end in tears, probably for Labour and certainly for Britain if it gets that far. But you can't blame those who've never experienced any system other than the current one for thinking there must be a better way.