The designer Yves Saint Laurent once said that dressing is a way of life. In his view, clothes are not a mere accessory to life’s key moments, but integral to the moment itself. Fashion, then, is not just a hobby, but a methodology for living well. What Saint Laurent never made clear was whether this methodology can be applied to an ordinary, less fashionable life, where the best moments regularly include ordering a pizza from bed or hangover-crying to episodes of the Antiques Roadshow. But luckily, contemporary fashion has this covered with the current trend for comfort dressing.

Broadly speaking, comfort clothes are the kind of thing that you already own. Think of the old jogging bottoms you wear around the house and might even pop to the corner shop in; the stretched, bobbly jumper that your relatives mock but you can’t live without; the oversized T-shirt you might lazily wear to your local but then fall face first into bed without removing. You have probably owned this style of clothing your whole life, but what is new is wearing it outside – and not just as a quiet trick you play hoping no one notices, but loud and proud. You’re comfy, and you want everyone to know about it.

It is the logical next step of a sartorial period in which streetwear and sportswear fused to become “athleisure”, where going from the gym to anywhere was stylish. Now replace gym with “sofa” or “bed” and you’ve summed up this latest style iteration.

Comfort dressing has crept on to the catwalks (see Stella McCartney, Prada and Chanel) and given birth to a whole new generation of comfort fashion brands, such as the effortless “bed to street” chic of Les Boys Les Girls. Naturally, the high street has responded: you can now buy a kimono jacket in Topshop – the traditional Japanese ceremonial gown that has long inspired sleepwear robes – while silky pyjama-style shirts can be found at Zara and Asos.

There is more to say about this fashion moment. Could the prioritising of women’s comfort be described as feminist? Or is it simply the result of a dystopian tech nightmare, where so much of our life is lived online that “innerwear” – clothes for wearing in private – are now our de facto uniforms?

Although I quite like the idea of everyone wearing their most relaxed clothes out in public with pride, the real test would be whether it is genuinely comfortable wearing pyjamas out in public or not, so I decided to find out.

At work in a Mickey Mouse nightie. Photograph: Alecsandra Raluca Dragoi/The Guardian

In theory, to achieve this look you can just wear items you feel happy hanging around your living room in. But in practice, comfort is a specific trend, and does not stretch to animal-print onesies or embarrassing tourist T-shirts. After consulting the Guardian’s fashion desk, I get hold of an Asos pyjama-style shirt, along with a pair of Marks & Spencer grey cashmere jogging bottoms and a jumper in the same shade. From my own wardrobe, I pick out a vintage oversized Mickey Mouse nightie; a Japanese-inspired kimono gown; and a pair of wide-leg plain black pyjama bottoms. I also want to find an oversized Lenny Kravitz-style blanket scarf, but settle on an actual blanket that previously belonged to my cat.

On the first day of the experiment, I go with the nightie-kimono combo teamed with my baggiest, comfiest jeans and trainers. When I was first asked to write this article, I thought it would be a breeze. I am someone who does not know the meaning of dressing up: I am devoutly casual, and have been a fan of sportswear since my teenage years.

But when I get to the door to leave my house, and the thought of being on the bus in my nightie becomes real, I chicken out. It feels wrong, which I realise is because I’d worn said nightie and gown as they were intended – as actual pyjamas – the night before. This is too extreme for even the most faithful of comfort-trend disciples: these clothes aren’t clean. Shoving them in the wash, I pop on the grey jumper and trouser combo that are so close in shade they look like a two-piece. It’s not every day you get to cover yourself top to toe in cashmere, and the close, sleepsuit fit makes me feel like a big rich baby. I love it.

When I was growing up on an east London estate where people did genuinely wear their pyjamas outside, I was told that to get ahead I should dress smartly. It would incense me that at university, the posh kids could slip around in joggers, whereas if I did I’d bring myself to the attention of security staff at Boots. Yet, in my cashmere babygro, I don’t feel especially visible, just comfortable. There is safety in numbers, and I suppose as enough people are dressing this way, I needn’t worry as much.

I am, however, much more visible at work. Not in a disciplinary way, more in an envious way. “You just look so comfy,” says a colleague as I walk past. “It feels so soft,” says another, stroking my arm. It is unclear if the clothes make me feel like it is a particularly relaxing day or if it actually is, but I am so chilled out that I fall asleep on the train home from work. Later, when I am lounging around my house, I am struck by how hot the outfit is. I become irritated and pull it off.

The next morning, I put on my (now clean) nightie and kimono and head back to work. It is cold, so I keep the gown closed and enjoy the feel of silk against my skin. It is luxurious and genteel: I feel I could also wear a cravat and smoke a pipe.

Drinks with friends in pyjamas and a cat blanket. Photograph: Alecsandra Raluca Dragoi/The Guardian

No one on the tube bats an eyelid. I receive no judgmental glances. No one mentions anything at the office, either. Eventually, after a bit of prompting, a colleague says: “Those jackets are in shops now. It just looks like one of those.” Fine.

I turn it up a notch, undoing the gown to reveal Mickey as a wizard; I am walking past desks slowly, flapping my kimono around in the hope that someone will notice. I ask someone’s opinion of my nightdress. “I don’t know. Looks retro. Just assumed it was some hipster, trendy thing.” This, I realise, is why my experiment may not produce substantial results. As a millennial working in the media, who already dresses informally, I am able to get away with a lot under a presumption of fashion. The real test would be someone with a smarter work dress code.

The next day, I try out the black pyjama-style shirt – that is, a shirt with the trims of a silk pyjama top (piping around the collar and pocket). This design is made from a material that is closer to a suit jacket and would definitely not be worn to bed. Paired with my black pyjama bottoms, on first glance it does look like a set, but technically speaking could be worn to an important meeting. Again, no one says anything, but I notice a few curious glances. When quizzed, the only noteworthy comment is: “Isn’t wearing makeup cheating? I thought the look was straight out of bed?”

For my final outfit, I want to test out the oversized blanket scarf (read: actual blanket). To give it the space it needs to be star of the show, I opt for the black pyjama bottoms and a black hoodie. The first thing to say is that wearing a blanket as a scarf – keeping it bunched up around the neck and shoulders – is actually pretty tough. You have to twist it up before it goes on and spend some time shaping it to get that just-thrown-on look. I wear it to Christmas drinks with friends, and aside from slowly dehydrating under all the layers, feel the confidence of a fashion insider. And at the cold bus stop, I am grateful for the full-bodied scarf. Why this has taken so long to catch on is beyond me.

Saying that, it is a relief to be back to normal the next day, and I’m not sure if I will be wearing my comfort clothes to work again any time soon. It strikes me as a little pointless to change out of one pair of pyjamas into another, particularly if they are designed to look more comfortable than they actually are.

The experiment has certainly made me think about the concept of comfort itself. To some, comfort is the feel of a certain material on the skin; for others, comfort it is about invisibility; and for others still, it is about being seen. I’m not sure which version is for me and suspect it changes daily depending on what sort of mood I am in.

But mostly, it has made me think about how you can wear almost anything and be guaranteed a polite smile. “Back in your civvies, I see,” says my colleague who had previously claimed not to have noticed. “Shame, I was just getting used to that.”