'Aquaman' director James Wan explains why he thought it was a safe superhero movie choice. And why he was wrong.

• Director James Wan chose to make "Aquaman" because he thought it was the superhero "everyone makes fun of," so he'd get to make it under the radar.
• It backfired as "Justice League" bombing at the box office put more pressure on "Aquaman" to succeed.
• Wan told Business Insider why making "Furious 7" helped prepare him for the pressures of making the DC Comics movie.

Director James Wan thought he had made the perfect choice when he was offered to do a superhero movie three years ago.

"They asked me which superhero I would be interested in, and I picked Aquaman because it's the one everyone makes fun of, so there wouldn't be a lot of pressure," Wan told Business Insider. "I'll go and make this movie under the radar - no one is going to care. Fast-forward, and there's just this massive spotlight on it."

What Wan didn't foresee was that the DC Comics Extended Universe would suffer a major blow when last year's release of "Justice League" became a major box-office and critical bomb. Suddenly, "Aquaman" was a pretty big deal for Warner Bros.

If Wan - the horror maestro behind "Saw" and "The Conjuring," as well as title holder of the biggest box-office earner of the "Fast and Furious" franchise with "Furious 7" (over $1.5 billion worldwide) - and his lead Jason Momoa couldn't make "Aquaman" a global hit, then what kind of future would the DCEU have outside of successful "Wonder Woman" movies?

Thankfully, "Aquaman" has become a box-office sensation, having already earned over $300 million overseas and becoming the highest-grossing Warner Bros. movie ever in China. It finally hits theaters in North America on Friday.

Read more: Business Insider ranks the 11 best movies of 2018

Wan admits there's always pressure one a big movie, but he said having made a big movie for a studio, "Furious 7," prepared him for all the anxiety of making "Aquaman" under a magnifying glass.

"It trained me to understand what it means to do a movie like this, but also how to have a movie like this fun in a way that people will endear it as opposed to scoffing at it," Wan said of making "Furious 7."

And US audiences are starting to see that for themselves, as the movie took in $13.7 million in preview screenings before its Friday opening, which is slightly better than "Venom" and "Wonder Woman."