In between stops on his massive 2018 Graffiti U World Tour, country superstar Keith Urban had a very special anniversary to celebrate on Monday (June 25): He and wife Nicole Kidman marked 12 years of marriage.

What began as a whirlwind romance between the Australian power couple has, over the years, come to be one of country music's greatest happily-ever-after love stories. Urban and his wife have never been shy about showing off how they feel about each other; just a few days before their anniversary, in fact, he led an entire crowd in singing "Happy Birthday" to her, and recorded the whole thing on his phone to send to Kidman.

On his Graffiti U Tour, Urban shares the stage with opening act -- and newlywed -- Kelsea Ballerini, who told The Boot and other media outlets backstage during the 2018 CMA Music Festival that she's learning a lot from Urban and Kidman about how to make a marriage between two busy celebrities work. Still, Urban has openly admitted that he wasn't always great at relationships: In the late '90s and early 2000s, he struggled with drug and alcohol use, exacerbated by his insecurities about his place in the music industry, until his marriage nearly imploded and -- at Kidman's behest -- he went to rehab.

These days, Urban's life is good, his marriage is strong, and he has much to be grateful for -- but, he says, he's always working to better himself: "I'm a work in progress," he told The Boot and other media outlets backstage at CMA Fest.

"We're just like any married couple, trying to figure out what works and what doesn't work," Urban adds. "Trying to balance work and family life is challenging for everyone, and it's no different for us."

Urban goes on to say that, if he and Kidman do have a secret for their success as a couple, it's their unwavering commitment to each other: "We're very, very 'in it' as a couple: very awake, very present and very in love," he says.

"When it does go out of balance," he continues, "we fix it quickly. We do whatever we've got to do. We travel, we do whatever it takes to not be apart."

Urban notes that nearly losing both his family and his career to drugs and alcohol left him with a lasting sense of gratitude "for everything I get to do."

"To be married, have children, play music for a living -- all I've ever wanted to do is play music and travel around like a troubadour and try to bring some light and joy [to the world]," he says. "The fact that I get to do that every day is not lost on me.

"It's a short life; it's super-short," Urban adds. "I don't wanna miss any of it, because I think I missed out on a lot of it."

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