Matt Damon isn't ready for his daughter to leave home.

The 53-year-old actor is coming to terms with the fact 18-year-old Isabella is preparing to start her studies at New York University later this year as it doesn't feel like so long ago that she was just a baby.

Matt - who has Isabella, Gia, 15, and Stella, 13, with wife Luciana and is also stepdad to 24-year-old Alexia - told E! News: "I called my friends and asked them how they dealt with it. What happened to them?

“It’s a lot. It’s a surreal kind of time and the way it operates in your life, the older you get, because it just feels like I was holding her yesterday

“To our relatively new parents, it happens quickly.”

Matt's 'The Instigators' co-star - who has Indiana, 20, and 16-year-old Atticus with former partner Summer Phoenix - understands his friend's feelings.

He said: “It feels like goodbye, you know what I mean?”

The pair got to return to their native Boston to shoot 'The Instigators', but the 'Good Will Hunting' actor admitted he didn't quite get the homecoming experience he'd imagined.

He said: “We shot some here, some in New York, but it was the first time I'd come back to Boston.

“Actually, all of my family isn’t here anymore. Like my mom was actually out of the country and my brother was out of town. So it was, it was very odd.”

Casey joked: “That happens sometimes. I get off the plane and I expect it to be like, ‘Cheers!’ Like, ‘Hey, Boston!’ And, like, no one knows you.”

Matt previously admitted Isabella loves to mock his career.

Asked on 'CBS Sunday Morning' if fans still associate him with his breakout movie 'Good Will Hunting', he said: "Sure, yeah—fewer and fewer.

"You know, younger people don't know it as much. You know, [Isabella] refuses to see it. She doesn't want to see any movies that I'm in that she thinks might be good."

Speaking about his 2017 flop movie 'The Great Wall', he laughed as he added: "She just likes to give me s***.

"My daughter said, 'Yeah, remember that movie you did, 'The Wall'?' I said, 'It was called 'The Great Wall'.' She goes, 'Dad there's nothing great about that movie.'

"She keeps my feet firmly on the ground."

But the 'Stillwater' star insisted his daughters are proud of his career and very supportive.

He said: "I like that they know that they love my job. They know it's time-consuming and that it's a lot of work and that it fills me up."