George Clooney insists Hollywood stars are "not allowed to get old"

He told Empire magazine: "You really do live your life through people's actors and pictures.

"And you're not allowed to get old. I have people come [up to] me all the time saying, 'You're a lot older than I thought.' Like, f*** off! I'm 64!"

Clooney reflected on a scene from the film where his character is watching his life on screen, and the clips are all from the actor's other real life roles over the years.

He said: "There's a weird thing where the older you get, the more you look at this stuff and go, 'Wow, that was a long time ago.' From my eyes, it was a minute ago.

"That's why I love that line in the movie when [a fan of Jay Kelly] says, 'When I see you, I see my whole live'.

"I get it, man. I became friends with Gregory Peck and I felt like that.

"I'd be sitting there with him, he'd be telling a story, and I'm just watching him thinking, 'Dude, this guy's in To Kill A Mockingbird!' You know where you were when you saw The Omen the first time. Roman Holiday."

Clooney also reflected on the people he's met along the way, noting that his longtime security guard - who he's known for three decades - has a role in the new film.

He revealed: "The fun part for me is, Giovanni [Zeqireya], the guy who plays my security guy in the movie - he's actually my security guy. I've known him for 30 years.

"He's more than that, he's also a really dear friend and he runs our house in Italy. I met him here at the Venice Film Festival, actually.

"We had to do that scene [in Jay Kelly] where we're running through a field. We do it like three times and I go, 'I'm 64 years old! I can't run, and he's seventy-f******-one!'"