There is the on-screen character he calls "Shatner", the brash Hollywood actor who never says no. Then there's "Bill", dressed in old blue jeans with his face sunburnt and sweating slightly in the spotlight.

"As I see the end of my life approaching, I am in despair and anxiety and, uh, bewilderment and fear and anger that it's over so quickly," Bill says, between sips of black tea.

"And yet, I am moving towards the awe and wonder of the universe. So it's all dazzling."

Dazzling still for the star of Star Trek, Boston Legal and such horror films as Kingdom of the Spiders and Miss Congeniality 2: Armed and Fabulous. He is 83 and reckons the key to living well is denial.

"That's the secret – you're not going to die, everything's going to be fine," he says.

On screen, Shatner speaks with his signature halted cadence, like a man reciting morse code. In person, Bill tends to ramble.

Unlike many people in Hollywood, he does not take himself too seriously.

"Everything is laughable," he says. "There's the cosmic joke and then there's this, and it's fun and you play along with it. Sometimes it gets a little less than a joke but. generally, the life that we're allowed to live has humour to it.

"If you don't laugh, you'll have to cry and you don't want to spend the precious moments that is your life weeping."

He is in Sydney for this weekend's Oz Comic-Con, with scheduled appearances between information sessions on "nerd activism" and an introduction to leatherwork.

He has been visiting the Great Barrier Reef and has sunscreen in his eyes. He perches forward in his seat for photographs. "I feel like I'm on the toilet," he says.

A comic book adaptation of his science fiction novel Man O' War will be published in October, in which a younger and thinner version of Shatner saves Australia from "chocolate Nazis". But instead we talk about his music, notably his fourth album Ponder the Mystery, released last year.

It is a dark trip, veering between spoken word space odyssey and the misery of a man on a beach watching the sun wane.

"You know, I've done some things that are cool but it could have been so much cooler," he says.

Perhaps he is referring to failed marriages or poor film choices but I don't get the chance to ask. Bill has more media interviews to sit through and orders a second cup of tea.

A journalist asks to pose with him for a photograph. "That will be $25," Shatner says, laughing.