This week, we’re naturally preparing for one of the newest traditional events in the nation’s calendar: Black Friday. It’s that raucous bacchanal of retail-related violence, a time when stores offer one-off promotional sales to trigger the customers’ greed-glands and jump-start the Christmas shopping season with a spectacular punch-up in a crowded space.

The tone has been set by the Hamleys Christmas toy parade in London, in which 800,000 people crushed into Regent Street, apparently attracted by the prospect of a “meet-and-greet” with Peppa Pig that sadly had to be cancelled at the last moment on safety grounds. As it was, a middle-aged woman reportedly had to be taken to hospital after being knocked to the ground in an affray with another woman – the colourful figures of Fireman Sam and Postman Pat on the parade route evidently failing to have an emollient effect.

For shopping-averse people such as me, any day with shopping in it is a black day, and Black Friday is most worrying of all. However, I can see the reasoning for retailers. Why spend a lot of money on newspaper ads, when you can offer 50 iPhone Xs at £5 each to the first 50 customers? Media coverage of the resulting riot is, as they say, priceless.

Poetic justice for Mugabe

And so farewell to Robert Mugabe, thought to be leaving Zimbabwe for a well-earned retirement in Dubai where he has a 10-bedroom property. It is hard to reconcile images of the ageing, cynical tyrant with memories of him as a younger man: dynamic, idealistic – and a lover of poetry.

One of the most poignant portraits of the former president has been given to us by the Guardian’s former Africa correspondent, James MacManus, who interviewed him in 1974. Mugabe told him that while a political prisoner in the 60s he conceived a great love for the work of TS Eliot. Afterwards, Mugabe begged MacManus not to mention his passion for Eliot in the interview, clearly afraid that he would look in hock to the colonialist culture.

Yet Eliot could have remained an influence. Maybe Mugabe saw himself as like Thomas Becket in Eliot’s Murder in the Cathedral, sitting tight in his presidential palace, waiting for martyrdom. Perhaps in Dubai he will ponder the lines from The Cocktail Party: “What is hell? Hell is oneself./Hell is alone, the other figures in it/Merely projections. There is nothing to escape from/And nothing to escape to. One is always alone.” Well, Mugabe has the satisfaction of knowing his presidency ended with a bang.

Dowsing and dunking

Water companies are in deep trouble for using “dowsing rods” to detect water – an irrational medieval practice that many say has no place in 21st-century Britain. A householder in Stratford-upon-Avon was startled to see an engineer from Severn Trent walking around with two bent tent pegs to find an underground pipe, waiting for them to magically cross. Reading this story, I felt like the judge in the 1998 grievous bodily harm case at Newcastle crown court, in which a juror wrote him a note, asking what star sign the defendant was.

There’s no evidence that dowsing works. But they will keep doing it, because of the illusory pattern of coincidence. Police officers searching for a body will occasionally admit to following up on leads offered by self-proclaimed psychics, because of the possibility that there is real, conventionally gathered, information.

It all feeds into the endless hunger for irrational mumbo-jumbo. Perhaps water company CEOs need to be examined for witchcraft, by dunking them in water.

• Peter Bradshaw is the Guardian’s film critic