It turns out all it took for Zac Efron to reveal his reasoning behind secretly checking into rehab for a substance abuse problem last year was Bear Grylls.

Efron appeared on NBC’s Running Wild With Bear Grylls on Monday night, where he opened up about his rehab stint while taking on the wilderness of New York’s Catskills.

"The challenging part was never the work. That was never it," he explained. "It was sort of the in-between work—the social aspects outside of it. I mean, everywhere you go to a certain extent, there is press in some form."

Efron shot to fame in his teens after his role in the High School Musical films, and he’s continued his career beyond that in films like Neighbors and The Paperboy with Nicole Kidman.

He went on to explain that whether it was an event to promote his work or just going to the grocery store, there was paparazzi or press.

"You spend a lot of time in your house, going crazy and pretty soon you need a social lubricant. And once I needed that, it became to go anywhere,” he said, E! Online reports.

Back in April, Efron spoke about his “never-ending struggle” with addiction with The Hollywood Reporter.

Despite rumors he went to rehab for cocaine addiction, Efron has never revealed a specific addiction. “It's never one specific thing. I mean, you're in your 20s, single, going through life in Hollywood, you know?” he said.

image via INFphoto.com