He says he's gratified by the overwhelming response to the film: "It's beyond what we could have hoped for," he says. "I don't think anything has even come close to that for me."
Ask anyone who's met Damon, or even just seen him on television, and they'll all tell you the same thing - that he's a great guy. Noel, a burly "minder to the stars" who's done security for Damon for all the Bourne tours Down Under, tells me Damon is by far the best star he's worked for in all his years. But Damon insists he's just a normal guy who's polite. It's not that he's especially nice; it's just other stars can be especially awful.
"You get more credit than you deserve as a celebrity. Like you say 'Hello' to someone and they go 'Oh, he's a nice guy'. And maybe the other thing is most actors are pricks. I don't know, but that's the sense I get."
So all Damon has to do to be a great celebrity is not to be a prick?
"That's it exactly!" he laughs. "The bar is set so f...ing low ."
And what hopes are there for a fourth Bourne film?
Damon says the story has reached its natural end and there are no plans for another sequel. But later that night at the Sydney premiere he leaves the door open, telling the audience: "If you like it enough, the studio will probably make me do another one."