TORONTO -- You don't need to remind Nickelback's Chad Kroeger that he recently turned 40 -- wife Avril Lavigne has been doing so for a year already.

Lavigne and Kroeger celebrated major birthdays just months apart but he said they had vastly different responses to their respective milestones.

He tells The Canadian Press that Lavigne seemed to think her 30th birthday was a "big one" but he "really just didn't care" about his own anniversary.

Nickelback recently released its eight album, "No Fixed Address."

The album was assembled at various studios around the world, in part because Kroeger and Lavigne have such a hectic schedule.

And he said that his comfort in turning 40, by the way, was motivated by the fact that he's content overall.

"I really just didn't care. I think that if you're happy where you are in life, it doesn't matter how old you're turning," said Kroeger, seated next to guitarist Ryan Peake. "If you're unhappy in life, each birthday you have -- especially the landmark ones -- tend to be a reminder of how much time is slipping away and you haven't accomplished or found that person or whatever it is in your life.

"It's not so bad when you're happy. I got a great gig; I get to play music for a living. And I'm married, so turning 40 is no big deal."

In a twisted way, it perhaps helped that one particular person close to him has been prematurely aging him for a while.

"The wife's been calling me 40 -- the entire time I was 39 she was like, 'Yeah, but you're 40,"' he said with a laugh. "I was so numb to it. Literally, halfway through being 39 I was telling people: 'Well I'm 40, so what difference does it make?"'