Everyone knows a Katie: The 'Katie' friendship theory that's shockingly true.

Everybody knows a Katie.

Katie likes to message at 7:07pm to tell you she’s very sorry, but she’s running a little bit late due to unforeseen circumstances and will be there in 10. She turns up at 7:33pm puffing and profusely apologising, muttering something about her dog’s sore foot and how she thought he might need surgery but in fact it was just a bindi so not to worry (no one was worried).

Katie sometimes replies to your messages straight away, and sometimes she takes two and a half weeks. There is no in between.

Katie leaves her passport in airport bathrooms, and her driver’s license on the bar. Her wallet is on a bus on its way to the other side of the country, and her phone is most definitely cracked in three places.

Katie doesn’t know if it’s June or maybe early March. Her calendar app doesn’t work and no one knows why. She bought a diary from Kikki K for $45, but she lost it in February. Luckily she wasn’t too fussed because it had nothing written in it anyway.

Katie might need reminding to transfer you that money she owes you from drinks, and unless you write it on her hand, you are not getting that book back.

And the thing about Katies, is that they’re always friends with Nicoles.

LISTEN: Every woman knows a ‘Nicole’. Post continues…

Australian comedian Geraldine Hickey introduced us to Nicole at the Melbourne International Comedy Special.

Every group of friends needs a Nicole, especially on holiday, she explained. “Nicole comes in and she’s like: ‘Righto girls, this is what we’re doing! Buffet finishes at 10, you want to get there before 9:30, that’s when they stop cooking the pancakes, you want to get in on those pancakes, they’re good pancakes.

“The first bus leaves from the hotel at 10:15, we’re going to be on that bus for a morning of shopping.

“I booked us in for lunch at this place. Here’s the menu if you want to have a look so you know what to order before we get there.’”

She’s happy to accommodate you if you’d like to go snorkelling today, but you will need to put it in the communal Facebook group she’s set up for organisational purposes.

You can watch Geraldine Hickey’s musings on Nicole, right here. 

If anyone’s worried about getting lost, Nicole has you covered. She will be wearing a bright pink top, and she’ll always be waving a big stick with a scarf tied to the end.

Without Nicole, you’d wake up at 3pm, with no idea where/who you were, and then just walk around in circles like a dog chasing it’s tail.

But the more one thinks about Nicole, the clearer it becomes: The world only needs Nicoles because there are so many goddamn Katies.

Katie confidently walks in the wrong direction while Nicole gently asks if she knows where she’s going.

Katie says she’d like to catch up for coffee, but that won’t happen unless Nicole names a time and a place and allows for two to three reschedules.

In fact, when she truly thinks about it, Katie only goes out – for drinks, to the movies, to a play – because Nicole organised it and talked her through directions while she was having a little bit of a panic attack in the car.

Nicoles are the glue that keep friendships together.

Katies add some entirely unnecessary chaos – but their primary job is simple.

Stay the hell out of Nicoles way.

And please, for the love of God, please stop leaving your wallet in public places. It will send Nicole to an early grave.

READ MORE: The ‘Nicole’ friendship theory might just be the truest thing we’ve ever heard.