The 43-year-old country singer said there were 'a lot of reasons' why he kept his distance from his girlfriends before meeting the actress.
He told Good Weekend, 'It didn't help that we moved around a lot when I was a kid. I went to a lot of different schools. I never made really close friends. I guess that develops your personality.
'I think the truth is I've spent my whole life fearful of intimacy. Just never getting close to anyone and not letting anyone get close with me. The result is this feeling of 'being without', this hole that I tried to fill with all those other things. The only thing that has really filled it has been the love of my wife and our daughters.'
Urban had to enter rehab for drug and alcohol abuse shortly after walking down the aisle with Kidman, and admitted that he wished things could have been different.
He said, 'Would I have liked her to have met me as a good, solid, sober man? Sure. But at the same time, this foundation that I now live on was built with the two of us. It's beautiful. All I know is that the way in which it happened has turned out to be divinely inspired.'