Matt Damon would “never sell” out a director.

The actor-and-screenwriter says once he has agreed to appear in a movie or has hired a filmmaker for the project he could never get rid of them, even if he didn’t think it was working out, because he’d already committed to the project.

He told Men’s Health magazine: “My movies being really good or watchable always depends on everybody being really good, not just me. I’m particularly sensitive about making sure we secure the best possible people in each role because I am not somebody who can overcome if we don’t.

“And then, for me, once I make that commitment, I never will sell the director out on that project. You cannot change horses midrace. Even if your horse is losing, you ride the horse as hard and as fast as you can. If there was a mistake made, it was made in your initial decision to work with that person.”

Matt – who is currently starring in thriller ‘The Adjustment Bureau’ alongside Emily Blunt – also revealed he and writing partner Ben Affleck never take offence when their ideas are criticised by the other person.

He said: “When one of us comes up with an absolutely f**king horrible idea, which happens all the time, the other person, without batting an eyelash, says ‘That’s a terrible idea.’ And neither of us has our feelings hurt, and we just kind of move on.”

Matt Damon is more content with life now than he was 10 years ago.

The 40-year-old actor — who has four-year-old Isabella, two-year-old Gia and three-month old Stella with wife Luciana, and is stepfather to her 11-year-old daughter Alexia from a previous marriage — didn’t mind reaching the milestone age recently because he has fulfilled his personal goals.

He said: “It’s a good birthday – because a lot of the bigger questions are answered.

“I’m married with kids, all the things I was worried about at 30 I don’t worry about any more.”

Though Matt is content with his personal life, he still has professional ambitions he wants to achieve – including working with his friend Ben Affleck again.

He told Empire magazine: “You don’t always get to work with the people that you want to. I mean, I haven’t worked with Ben in years and he’s my best friend.”

Matt and Ben shot to fame after co-writing and starring in ‘Good Will Hunting’ together in 1997.

The movie earned them the Oscar for Best Writing in 1998.

Matt Damon says that he is happy to have turned 40 because all of his ‘bigger questions’ have been answered.

The married father-of-three said that he was happy to reach the milestone because he has everything that he wants.

He told Empire magazine, ‘It’s a good birthday – because a lot of the bigger questions are answered.

‘I’m married with kids, all the things I was worried about at 30 I don’t worry about any more.’

The actor shot to fame alongside best friend Ben Affleck after they co-wrote Good Will Hunting in 1997, and he said he hopes to be able to team up with his buddy again sometime in the future.

‘You don’t always get to work with the people that you want to. I mean, I haven’t worked with Ben in years, and he’s my best friend,’ he added.