Wild How I Met Your Mother theory changes a major plot point

A new How I Met Your Mother theory could open a whole new can of worms. Photo / Supplied

There are simply some facts in the sitcom world that we know to be true.

Monica Gellar likes things clean. Jerry Seinfeld wears jeans and white sneakers. And Barney Stinson is a womaniser.

But one of those facts may be about to turn on its head.

How I Met Your Mother fan 'Gingersaurus' - who clearly isn't over the 2014 finale (just like star Alyson Hannigan) - has pointed out on Tumblr that it's entirely possible Barney's 'Playbook' and associated sex-obsessed ways may be the result of a very biased recount.

OK, bear with us.

So as the entire series was narrated by Future Ted, who ends up marrying Barney's ex-wife Robin - it meant Ted and Barney were actually love rivals.

Despite their close friendship, it'd be fairly standard human behaviour for Ted to exaggerate certain aspects of Barney's character to paint him in a more negative light to his children.

Especially as he ends up getting their approval to go after Robin.

Even if Ted wasn't trying to actively shade Barney - every good storyteller knows to exaggerate the narrative.

So here it is: Is Ted an unreliable source?

Possibly. It could explain Barney's extreme behaviour (the Canada hate, the obsession with suits). Or maybe that's just how he is.

Either way, there's a chance we'll have more opportunity to analyse the situation: various members of the cast have hinted they'd be up for a revival, while 20th Century Fox boss Dana Walden threw her support behind it earlier this year.

"I hope we will have an opportunity to revisit these characters and tell these stories if [the creators and stars] have the desire to do it.

"It's a beloved show that still continues to be popular all over the world."