Matthew Mcconaughey's three children have made him more compassionate and selfish.

The 44-year-old actor, who has sons Levi, six, and Livingston, 22-months, and daughter Vida, four, with wife Camila Alves, says they are his number one priority and have brought ''clarity'' to his life.

Asked about being a father, the 'Interstellar' star told the November issue of GQ magazine: ''It's the one thing I've always wanted to be. Never is a man more of a man than when he is the father of a newborn. Whatever decisions you make in the first six months of becoming a father, double down on them. I mean, you're meeting the Courier. You're meeting the Shepherd, the Future Prince. You immediately have something you don't have to think about. You know what's important. Bam! And the clarity of that is like, 'Whew.' I definitely got more selfish. And at the same time, I think I got more compassionate, which don't always go together, you know?''

But the Oscar winner admits Brazilian model Camilla, 33, had to give him an ultimatum before he proposed and married her in 2012.

He said: ''I had to get to the point where I saw it [getting married] as more than just the thing to do. I wanted to really want to. You know, I didn't want it to be a destination; the fun is that we're on the adventure together. And look, some of it had to do with her putting it on me. It took her going, 'C'mon, Big Boy, Mr. Easygoing-We'll- Get-to-It-When-We-Get-to-It. Either s**t or get off the pot.'''