When the magical hour approached during Keith Urban's New Year's Eve gig in Canada, the country superstar once again showed his unwavering love for his Oscar-winning wife Nicole Kidman. He invited the acclaimed actress on stage and--in front of 60,000 fans--planted a passionate kiss on her lips as the clock struck midnight. Kidman had clutched her husband's face while he leaned forward for the kiss.

This singer and actress's loving embrace in Niagara Falls was the latest in an ongoing array of PDAs--public displays of affection--by the power couple. Even though their truly awkward first meeting didn't seem to hold any romantic possibilities and even though Kidman had to help the country star conquer his cocaine addiction just months after their wedding, their marriage has evolved into an enviable, rock solid union.

While a guest on the "The Oprah Winfrey Show" in 2010, Urban recalled his somewhat rocky first encounter with Kidman in January 2005.

Looking back, Keith admitted he was a little intimidated when he first met Kidman. They were at an event called "G'Day L.A." in Los Angeles where they were both being honored when he spotted her backstage. "I swear to you, she glided across the room, like floated," Keith remembers. "I don't know how she did it. It's like she's standing there, and she didn't walk. It was out of this world."

When Keith saw the actress standing alone for a moment, he gathered up the nerve to say hello. "I plucked up the courage to go and do it, very nervously, and trying to be all cool," he says. "[I] introduced myself and she was very pleasant and everything, and there was that moment of waiting for the next thing to be said-of which I didn't know if I was bothering her or what was going on-so I just sort of said, 'Well, nice to meet you' and I just walked away."

Later, a friend convinced Keith to try talking to her again. "I went back over and apologized, and we just started talking and just really clicked," Keith explained.

And click they did. They were married June 25, 2006 in Australia and immediately settled in Nashville, Tenn., where they later became parents to daughters Sunday Rose and Faith Margaret. Kidman also has adopted children Isabella and Connor with her ex-husband Tom Cruise.

A few months after the wedding, Urban told Winfrey that he was faced with a decision. An addiction to alcohol and drugs--mainly cocaine--had taken over his life. "I had to make a decision which road I was going to take, once and for all," Keith says. "I'd been at that crossroads before and always taken the wrong road."

"What was different about this time?" Winfrey asked.

"Love," Keith admitted.

At the time, Keith says he knew that if he didn't surrender and commit to overcoming his addiction, he'd repeat past mistakes. "[I thought], 'So maybe if I really want to be courageous and adventurous, let's take the road less traveled this time,'" he says. "It was a huge hole in my life that was going to be filled by the right thing eventually, or it was always going to be filled by the wrong thing."

Reality hit home when Kidman and a few close friends staged at intervention for Keith. "It was really a profound moment in so many ways. Then, the way in which Nic handled that moment was just perfect," Keith says. "Everything was just designed, I believe, for that moment to fuse us together."

At first, Keith says he questioned whether he should go to rehab so soon after getting married. "[I thought], 'Surely let's give it a few years so we've got some solidity, because this kind of thing could tear us apart,'" Keith says. "'This could just destroy us.'"

Ultimately, he decided it was time to get help. Keith left the same night as the intervention for treatment. "I just said, 'I don't want to do anything but go,'" he says. "I didn't care about anything else."

While in treatment, Keith dealt with issues that he says contributed to his alcohol and drug use. What had he been missing? "A sense of being centered and connected with something greater than me," he says. "You can call it what you like, God. There are a million names for it. But, ultimately, for me, it's love. That's the thing that ... I was missing in my life. Love for myself."

Loving himself, he realized, would also help him love others. "If I don't have it, I can't give it away," Keith says. "I look back now and realize Nic has taught me so much and brought so much into my life and opened my eyes in so many ways."

Early in his relationship with Kidman, Keith says they went to a park. While sitting on a bench, he says he asked her, "How's your heart?"

"I didn't know why I asked that question," Keith says. "I'd never asked anybody that before. I don't know what answer I was expecting."

She answered, "It's open."

"It was not only beautiful because it said so much about her, but it instantly made me ask myself: 'Is mine? Is my heart open?'" Keith says. "'Or is it 80 percent open, but I've got a little exit strategy? If I do, then why is that?'"

As anyone who's ever loved and lost knows, once you've had your heart broken, it's hard to love again. For this reason, Keith says he was scared.

"I looked back and realized that I stayed in this pattern because I wasn't really loving," he says. "I hadn't met the right person. I wasn't the right person, but I wasn't really giving myself fully. I was holding back because I was scared."

It's clear that Urban transformed himself into "the right person" and it is equally clear that he has "met the right person" in Kidman. And another thing is also patently clear--the kissing and other types of PDAs will continue to be a part of their bond of two "open" hearts. That's who they are.