Jack Black Opens Up About What 'Surprised' Him Most as a Dad: 'How Much I Worry' [Exclusive]

"You just want the best for them and you spend so much time and energy just thinking about that," the father of two tells PEOPLE in this week's issue

Jack Black didn't anticipate just how much fatherhood would change him.

"What surprised me is how much I worry," the dad to sons Thomas "Tommy" David, 14, and Samuel "Sammy" Jason, 16, tells PEOPLE in this week's issue, amid the release of his new animated flick The Super Mario Bros. Movie.

For Black, 53, the actor remembers when Sammy was born knowing instantly that he "was signing up for a whole lifetime of just wanting the best for them."

"You spend so much time and energy just thinking about that," he says. "Also, it's harder than you think when you first start. Because you're always wondering, 'Am I doing this right? I don't know If I'm doing the right parenting thing.' But you do the best you can, and you hope for the best."

At the end of the day, though, "I just want them to be happy," says the actor-musician. "I mean, the hard thing is that being the child of a celebrity is not easy. It has some special stresses that are not [typical of] normal childhood stuff."

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Related:Jack Black Says His Son, 15, Wants to Make a Movie About Dad's "Hollywood Adventures"

Black — who has been married to the boys' mother, musician Tanya Haden, for 17 years — explains that parenthood just "makes you look at the world a different way."

"When you're looking at it as a parent, it adds a level of unexpected adulthood," says the Goosebumps actor. "Because I spent my whole life going, 'I'm never going to have kids.' Because I'm kind of a kid."

"So it forces you to say, 'Okay. Look, let's be responsible now. Let's figure out the right thing to do in all these different situations.' [Things] that you never really even paid attention to before," he adds.

Nowadays, Black recognizes the "luxury" of being around his family a lot — something he says he "rediscovered over pandemic times because we got to hang out all the time."

"And now that I'm back to work on the set of a movie, I really miss them," he admits.

RELATED VIDEO: Jack Black Reveals His Biggest Dad Fail as a Father of 2 Sons: "I Think I Blocked Them Out"

As for his own childhood influences, Black cites his stepdad — who, in particular, was part of the inspiration for his character Dewey Finn in 2003's School of Rock.

"My stepfather was a substitute teacher and he brought rap music and different elements to his teaching style. I just always thought he was so funny and interesting and quirky," Black tells PEOPLE.

The Tenacious D member says he also "took a lot of inspiration from a student in school [with me] named Steve Moramarco, who was a struggling rocker, who I just thought was such a great character study for that role."

"And it's a love letter to all the rockers who haven't hit the big time but have that dream in their hearts, because there's so many out there, and it's a testament to the dreamers," he adds.

The Super Mario Bros. Movie is in theaters now.

For more from Black, pick up the latest issue of PEOPLE, on newsstands Friday.

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Read the original article on People.