Matt Damon and Ben Affleck always thought they'd be able to pay back the "incredible debt" they owed Robin Williams.
Matt Damon and Luciana Barroso at the Golden Globes
The two actors' Hollywood breakthrough came in 1997 movie 'Good Will Hunting' - which they also wrote - and they always recognised that the film would never have been made if the award-winning star hadn't agreed to be in the movie.
And Matt still finds it hard to come to terms with his late co-star's suicide over two years ago because he always thought there would be time to repay Robin for helping them get their big break.
Speaking to E! News' Ryan Seacrest on the red carpet at the Golden Globe Awards on Sunday (08.01.17), Matt said: "Oh, man, [I have] a lot of Robin Williams memories, good memories of him.
"And Ben said recently, it's weird, we always felt like we were going to, we had this incredible debt to pay him back.
"And we thought there would be time to do that and just the abruptness of somebody leaving like that, that realisation comes that you're never going to be able to pay back this incredible thing done for you.
"That movie got made because Robin said he wanted to do it. That changed the trajectory of our careers completely, forever."
The 46-year-old actor - who attended the Globes with his wife Luciana Barroso to support 'Manchester by the Sea', which he produced - previously recalled how emotional Robin had made him and Ben on the set of the film as they realised their dream was being fulfilled.
He said: "It was the very first day of shooting and Ben and I went to the set. We weren't working that day and we just saw them rehearse and we were kind of sitting off to the side of the camera ... by the time they said, 'Action,' tears were just falling down my face.
"I couldn't believe it. I was just looking at Robin start to speak and say these words that Ben and I had just worked on for five years and I just looked up at Ben and the same thing, he was just ... And Robin was great. After the scene ended, he came over to us and he saw us.
"He put his hand on our head and just said, you know, 'It's not a fluke. You guys really did this. You really did it."
Tagged in Ben Affleck Matt Damon Robin Williams