THAT ONE TIME JAMES CAMERON FELT SMALL

It takes a big man to admit to feeling small.

Given James Cameron is responsible for the two highest grossing films of all time -- 'Avatar' and 'Titanic' -- he's a really, really big man.

And he's been on a really, really big adventure to the bottom of the Pacific Ocean, visiting the Mariana Trench 10,908 metres below sea level (and one you can catch in cinemas next week from August 21 in 'Deepsea Challenge 3D').

So what, then, was James's first thought upon touching down in the most remote and inhospitable place on the planet?

"[It was] just how small I felt, how remote from humanity [I was]," he told Yahoo7 Movies. "The vastness of the unknown around me -- there was a humility to that. And also an excitement. I knew that any place I saw, any place I turned my lights was going to be something new."

James and co-director Ray Quint at the Australian Maritime Museum in Sydney on August 8. Credit: Getty Images

The dive was some seven years in the making. So prepared was James in fact, that he brought a checklist for the bottom of the ocean that included "eat a protein bar, turn on the sonar."

Another surprising note on his list? "Stop. Look out the window. Think about where you are," James revealed.

One omission from his list that saw the great man chiding himself was leaving out the step of a "one small step for man" style quote. Something his co-director Ray Quint was quietly hoping for.

"I wanted Jim to say something as profound as that when he touched down at the bottom of the Mariana Trench," Ray laughed. "And of course, what he ended up saying was something like, 'I'm here. It's good.'"

We can safely say 'Deepsea Challenge 3D' is better than good. It's a valuable insight into one of the world's highest achievers and also just how much goes into doing the impossible.

PICS: 30 Movies to See Before You Die