"It's been a really good life and my children are living proof," he tells PEOPLE
Kevin Costner daughter loves Frozen

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He may be an Oscar-winning actor and director, but like most parents, Kevin Costner still plays “Let it Go” on repeat.

“My little girl [Grace Avery, 4½,] dresses up every day,” he says. “It’s the Frozen household. Everybody has to freeze when she says so. The boys [Hayes Logan, 6 next month, and Cayden Wyatt, 7½,] are just so sick of it!”

But for Costner, married to Christine since 2004, those family moments are what make life so fulfilling. “It’s really fun to see [all my kids] together,” says the dad of seven, who also has four grown children.

“It’s been a really good life and my children are living proof.”

Now starring in Black or White as a widowed grandfather fighting for custody of his biracial granddaughter, Costner, 60, is also relishing this time in his career — one that hasn’t been without a few bumps.

“I’ve had low moments,” he says. “But it’s how you behave in them. I don’t have that thick of skin, but I do know that I can’t operate my life with fear.”

Especially, when you have kids to answer to. “You can’t stop [to think] too long, because life keeps rolling anyway,” says Costner. “If you sit and ponder, you’re going to get rolled over, at least in my house you will. I have a 4, a 5 and a 7-year-old who don’t care what I’m thinking about if it’s not them!”

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

— Aili Nahas