But off screen, both actors take the same stance when it comes to family.
“They’re a part of me,” Elba tells PEOPLE in this week’s issue of son Winston, 3, and daughter Isan, 15. “They are the reason I get up and do it.”
“When it’s a hard day and I think about bringing them up, I go, ‘Thank you for existing so I have a purpose,’ ” adds the actor, who stars as protagonist Roland Deschain in the highly anticipated sci-fi western.
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The British star, 44, tries to instill a similar sense of purposefulness in his kids.
“I try to get them to be appreciative for what they have and who they are,” Elba says. “That’s a challenge in this day, just reminding the kids being here, what we’re dong right now, is real.”
McConaughey stays in the moment thanks to help from wife Camila Alves. “The person I’m most thankful for the things I’m getting to do — and we know it takes an army — is my wife,” says the dad of Livingston, 4½, Vida, 7½, and Levi, 9.
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“I don’t have to look in the rear-view mirror. Every day, she says, ‘Go, I got this.’ She drops things and goes with me, with the kids,” explains McConaughey, 47.
“So when I go to work or I head out the door to do whatever I have to do that day, I never have to look over my shoulder.”
Elba also has a special woman in his life. “My mom is tirelessly my No. 1 fan,” he says. “She used to say to me back in the day, ‘One day you’re going to be up there with Will Smith.’ And then I showed her a picture of me and Will Smith, and it blew her mind.”
The Dark Tower premieres nationwide Friday.
For more from Idris Elba and Matthew McConaughey’s life with their families, pick up the latest issue of PEOPLE, on newsstands Friday.