The detail you've probably never noticed about Kate Middleton

From her long, glossy hair to her dimpled grin, Kate Middleton's features are instantly recognisable.

Given just how many photos of the commoner-turned-royal are in existence, you'd think no detail of her appearance could have possibly gone unnoticed by the public over the years.

Alas, it seems the Duchess of Cambridge has been pulling the wool over our eyes.

(Well, in this case, the hair.)

Back in 2011, some extremely eagle-eyed royal fans spotted the mum of three's scar and became rather fixated on it, to the point theories began circling that it was a sign of wig extensions. (Seriously.)

Though the Royal Family seldom comments on public speculation like this, the palace did see fit to provide an explanation in this instance. A terribly succinct explanation, but one can't look a royal gift horse in the mouth.

"The scar is related to a childhood operation," a spokesperson told E! News at the time, providing no further context.

It's unlikely we'll ever hear the full story behind Kate's scar; to borrow a turn of phrase from Mean Girls, her hair's so big because it's full of secrets.

Not to worry, though: her husband has us more than covered in the 'facial mark with a back story' department.

RELATED: The sweet story behind Kate Middleton’s engagement ring

Prince William has a sizeable scar on his forehead that he refers to as his "Harry Potter scar" (future kings: they're Harry Potter dorks just like us).

"I call it that because it glows sometimes and some people notice it—other times they don't notice it at all," he said in a 2009 interview with a 10-year-old cancer patient named Alice.

The royal dad then explained his distinctive scar had originated from what one might call an 'airborne golf club' incident.

"We were on a putting green and the next thing you know, there was a seven-iron and it came out of nowhere and it hit me in the head.

"So, yeah, I was in hospital for that, but that was very minor compared to how many times you've been into hospital."

At this point, one has to wonder: what's the punishment for whacking the heir to the British throne with a golf club?