Last night, in my local Spar on Dublin's South Circular Road, I spotted two separate young women shopping in their pyjamas. On my way home I passed another. Her pyjamas, I noticed, were made of a material so thin it was almost see-through. I was wearing jeans, boots, a jumper and one of those stupid hats with plaits down the sides. It was not exactly a balmy evening.
That's the first thing I don't understand about the pyjamas-in-public phenomenon, which began in wet, cold Dublin in the early Noughties and has spread to certain parts of the UK. The girls who do it (I have yet to see a guy buying 20 John Player Blue in his PJs) must be bloody perished. Pyjamas are supposed to be about comfort, not freezing your ass off.
A film called Pyjama Girls, which opens next month, will attempt to explain the inexplicable. It focuses on teenagers from the Basin Street flats in Dublin's inner city, and according to its director, Maya Derrington: "There is a sense among the communities where pyjama-wearing is prevalent that the home doesn't stop at your front door. It's the wider area you live in. There is more of an old-fashioned sense of belonging, of an identity."
This is a positive take on what most would see as a fairly negative trend, which developed at a time when Ireland was listed as one of the world's richest countries. The girls who went out in their Penneys' PJs were a kind of defiant two fingers up to the lie that we were all rolling in it. Mooching on the corner in their nightwear, they were a vision of defiant hopelessness in a country that had fooled itself into believing the dream.
They wore their pyjamas like a badge of honour. "You have to have a grudging respect for that kind of statement," said one writer on the Pyjamas as Daywear blog. But the truth is that public pyjama wearing raises the hackles in a way that no other fashion fad has ever done.
In Britain, where the phenomenon is still in its infancy, there have been moves to turn the tide, instigated by that bastion of socio-economic correctness, Tesco, who have banned the wearing of pyjamas in their stores.
To drive their point home to their targeted audience, they made an example of working-class girl turned WAG, Danielle Lloyd, accosting her for her attire, which turned out to be a Juicy tracksuit, rather than a pair of PJs. "They must think they're posh," she Twittered. "I know I am terrible but I don't care what I wear to the shops."
And here lies the heart of the matter. There is carelessness to the wearing of nightwear as daywear that speaks volumes about where the young women who walk around in their PJs find themselves. They might appear cheeky, but their attitude looks to me like a front. More than laziness, their attire denotes the ultimate breaking down of the kind of self-preservation that makes the rest of us get out of bed, dress up and face into the world on a daily basis. It's like the final degree of despair displayed in soft cotton.
However, there is some light at the end of the tunnel. In an interview about her film in The Sunday Times, Derrington said that the girls she filmed change out of their nightclothes into day pyjamas. This has a sense of the radical about it that supplants my original thesis. They're buying pyjamas specifically to wear outside, which means they are actively subverting the dictates of fashion.
I'm 100% behind anyone who dares to stand up to the spread of MacFashion, where we're all forced to wear a global uniform handed down to us by high-street chains. Maybe I'll go and buy my litre of soya milk in my Calvin Klein PJs from Brown Thomas tonight.