A TikTok user has blown people's minds after sharing a 'hidden detail' from Back to the Future, 35 years after it was released.

The movie fan, who posts on the account @hiddenmoviedetails pointed out something very interesting about the mall where Marty meets up with Doc to see the DeLorean.

The user points out that when he first goes to the mall, it's called the Twin Pines Mall.

However later on in the film, when the character is coming back from the future, the mall's name is very different.

Instead, it is called the Lone Pine Mall and the man explains that it's not a mistake.

He says: "When Marty first went back to the past, he ran over one of these pine trees, which is where the mall would eventually be built.

"So Marty ran over the pine tree, which turned it into Lone Pine Mall when it was originally Twin Pines Mall."

The TikTok video quickly went viral, garnering over 21 million views and being shared all over the internet.

It was later shared on Twitter where it blew actor Josh Gad's mind.

He shared the clip, writing: "WAIT?!! WHAT?!!!"

Another person said: "I honestly seen this movie 100 times and never realized..I feel dumb now.."

A third wrote: "Details. It really is all in the details."

"I just learned this and it's 2021," proclaimed someone else.

However many people weren't impressed with the fact as they claimed to have noticed it years ago.

"I picked up on this when I saw it in the theatre when I was eight-years-old. It's been blowing my mind the past several years that so many never noticed," admitted a different user.

"As popular as these movies are, I'm offended some people didn't notice this," added a second. "The director placed it right in the middle of the screen."