It's not often that a fashion brand comes up with the winning formula for a universally-flattering piece of clothing. This is never more true than when you go to borrow something that looked amazing on your friend, only to put it on and realise it looks completely wrong on you: it hangs weirdly, or has bizarrely large armholes (just us?)
However, borrowing nightmares aside, high street favourite Zara appear to have achieved the impossible and produced a coat that looks good on just about everyone: and now just about everyone is wearing it.
The blue and white checked coat, which hit the high street earlier this year, has gone viral after being spotted on everyone from shoppers on the street to commuters on the tube.
The coat's adventures are even being documented on its very own Instagram account, @ThatCoat, started by London-based sisters Alice Frances, 28, and Emily Bray, 25, after they began seeing it everywhere they looked.
Speaking to Stylist.co.uk about That Coat, Alice said, "Often we would notice at least five or six other people wearing the coat at the same time. We just kept spotting it everywhere, and friends did too."
"We set up the Instagram account and started taking photos, and then friends also started sending them to us, and then complete strangers. It's been spotted everywhere: at work, on the street, at weddings, from Brooklyn to Paris."
So just what makes the coat, priced at a very reasonable £69.99, so popular?
Alice said, "It's such a versatile coat - the perfect item for the British woman's wardrobe. And women of all ages are wearing it!
"It's stylish but also quite a safe choice. The Chanel-esq cut gives it a luxury feel, and the blue and white print is distinctive without being too bold. It really just goes with everything."
Since the coat's Instagram account was set up just under four months ago, it has already amassed over 1,000 followers, with nearly 3,000 women tagging themselves - or strangers - wearing the coat.
And the phenomenon shows no sign of slowing down now that autumn is officially here.
"The coat is just getting started, we've seen a lot more since the weather has got colder," Alice said.
"I think lots of people were stashing it in their wardrobes ready for the winter! We've definitely not seen the back of #That Coat just yet..."
The coat is sold out online but you can still buy it in Zara stores across Europe - find your nearest stockist here.