Keith Urban believes marriage is like "a garden".
The 'American Idol' judge has grown to realize his relationship with Nicole Kidman - with who he has daughters Sunday, five, and Faith, two - needs to be "maintained" constantly.
He said: "Nic and I say, 'Balance is never achieved; it's just maintained.'
"I'm a guy, so I'm not used to having to maintain anything. I'm used to achieving something, and good, that's done, move on to the next thing. No, no, this marriage, this family, it's a garden. It's not fixed and then you move on; it's maintained on a daily basis. I finally get that now."
The 46-year-old singer admits it is only in recent years he has appreciated just how quickly life passes by.
He added in an interview with the new issue of People magazine: "Somewhere in the last couple of years, I've really grasped the concept of the brevity of time.
"It's very, very fleeting. No matter how many years are ahead of us, it will all be gone very quickly. I don't want to miss any of it."