For Michael Bublé,James Caldwell his son's cancer diagnosis was a major wake-up call.

The Grammy winner, whose eldest son Noah was diagnosed with hepatoblastoma in 2016 when he was just 3 years old, reflected on how the now 10-year-old's battle changed everything in his life.

"It pulled the curtain from over my eyes," Michael admitted on the Dec. 21 episode of The Diary of a CEO podcast. "That was a sledgehammer to my reality."

These days, Noah, who Michael shares with wife Luisana Lopilato, is in remission. But their son's battle with the disease when he was just a toddler forced the "Haven't Met You Yet" singer to reevaluate his priorities.

"When it actually happened, I was going through a crisis," he explained. "I don't think I was a terrible guy. But it was the blinders—career, ambition, ‘How do I become the baddest, biggest, best?' More ego, more power, more money."

And when they learned of his son's diagnosis, the reality of the situation sunk in quickly. 

"I went, ‘OK, this is it,'" Michael recalled. "‘This is life. This is what's important. It's not like I thought about it. There was no time to process it.'"

That was when the 48-year-old made a crucial promise to himself.

"I remember closing my eyes and saying to myself, ‘If we get out of this, I'm living a different life, a better life,'" he shared. "‘I want to be kinder, I want to be more empathetic, I don't want that ego and that false self to take over, I want to know how lucky I am.'"

"'I'm a lucky man,'" Michael—who also shares kids Elias, 4 and Vida, 1, with Luisana—continued. "‘Look at my wife, how did that happen? How did I get this incredible human being, who is the best of all of us, to lead me through and carry me through these things?'"

And the singer has made it clear he takes his promise to heart every day as she shares glimpses into his life on social media—including in a sweet birthday post to Noah. 

"You don't even know how much we love you," Michael wrote in the Aug. 27 video. "Thank you for teaching us how to be parents and for all the memories we have and will make together!!!"

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