"That was one of the things that we kind of wanted to do," Affleck, 50, said in a new interview with CBS Sunday Morning. "The idea of, like, why aren't we hanging out and spending more time together, since we managed to stay friends this whole time?"
"Plus, we hit our 50s," added Damon, 52. "I mean, you can see the end of the tunnel!"
The two say they're thrilled to reunite in their new film, Air, which tells the story of how Nike built an empire based on a shoe named for rookie NBA player Michael Jordan.
"It was just so much fun — I don't know. It kinda felt like just us and getting to do the thing that we wanted to do. I did. I loved it. I loved it. I miss it every day since. It was the best, like, work experience of my life, without question," shared Affleck, who also directed the film.
The dynamic duo grew up together in Cambridge, Mass., and spent years as struggling actors in Hollywood. But they skyrocketed to superstardom in 1997 with Good Will Hunting, for which they scored Oscars in the Best Original Screenplay category. Looking back, both men say they were shellshocked by achieving the honor so young.
"I remember it didn't settle in for ... a couple years, I think," Damon shared. "It was completely surreal."
"March of '98, I was 25 years old," Affleck said. "I look at myself now and think, I still have quite a bit to learn. You know, that's the curse of being 25, is you think you have it all figured out."
While their careers and personal lives have taken plenty of twists and turns in the decades since, Affleck says he's learned some important lessons in recent years— particularly about the endless pursuit of financial wealth.
"Frankly, one of the lessons of growing older is, it's not all about money. It's not the most important thing. You spend your life chasing money, you ... might end up with a lot of money, but you'll probably miss out on a lot of things. I haven't found that money changed any more happiness that I had," he shared. "In fact, that's the beautiful thing about this, is the happiness was being able to be here every day in Los Angeles with my children around, see them every day. Have them come visit the set. Work with my best friend my whole life. There's nothing more that I want in my life. I thought, Well, this is it. This is what I've always wanted, you know?"
Affleck also shared the joys of working with his wife, Jennifer Lopez, who will appear in Unstoppable, an upcoming project the duo will produce about Anthony Robles, an All-American wrestler born with one leg.
"What fun, what a joy to do something with her, see her be great, go to work with your wife, go to work with your best friend," he said. "Because ultimately, like, your work becomes the lion's share of what defines your life, in terms of the time you spend. And if you don't like who you're working with, and if you have difficulty or trouble at work, I think it's one of the things that can really cause depression, anxiety and pain for people. And conversely, if you love the people at work, you probably have a pretty good life, you know?"