"I only ever watch anything I do once," he said, at the National Film and Sound Archive in Canberra . "Because my work is done. There's nothing you can do for better or worse about it, so I've maintained that."

Except for one "highly irregular event" on Friday night when he watched – for the second time – his part in the film Children of the Revolution, which won the audience prize at the first Canberra International Film Festival back in 1996.

The festival celebrated its 20th birthday with a big gala celebration at the NSFA on Friday attended by Roxburgh and Children of the Revolution's director Peter Duncan, complete with a screening of a 35mm print of the film owned by the archive.

"Children was such a beautiful, eccentric, really madcap event in all of our lives," Roxburgh said. "It speaks of a different time when a film like this could get funding to get up in Australia. I don't think it would ever happen now."

It was Duncan's first film and it featured big names – Judy Davis, Sam Neil and Geoffrey Rush.

"When you're inexperienced, you don't know what's impossible and you go for things," he said.

The pair go way back and have continued to collaborate over the years, including creating the popular ABC-TV series Rake.

Roxburgh says the spark of the character that became the mercurial barrister Cleaver Greene was from an eccentric character from his ANU days.

"He wasn't even a student. He was just a guy who hung around the Union Bar," he said. "He could quote anything at the drop of the hat. Shakespeare. He would be up on the bar doing the Marx Brothers. He'd be wearing these baggy suits. He'd jump up on to the stage in the middle of Hunters and Collectors' sets and take over their piano and do Jerry Lee Lewis impersonations.

"He was brilliant and always being beaten up and that was the germ of the idea."

The pair are adamant Cleaver owes more to that ANU eccentric than real-life barrister Charles Waterstreet.

"Charles told us half of a story," Duncan said.

"It's nothing to do with Charles," Roxburgh said. "That's a great and popular misconception."

Roxburgh jokes he can only but regret switching from economics to acting.

"I spend a lot of time rolling around in the wee hours for a life poorly spent. 'What's the RBA thinking?' I'm constantly traumatised by that sort of macro-policy."

But his days on campus at the Australian National University were golden, moving to the big smoke from his hometown of Albury.

"I started at Garran Hall until my mother came and sort of sprung me from there because I appeared to be getting a pot belly from malnutrition, which was probably more likely apple cider at the Union Bar," he said.

"Then she put me in Burton until some forestry students started mowing the carpet at 4am one morning and I personally had to get out of there.

"I have a great romantic attachment to Canberra. It was that time of my life. I'd always wanted to come to Canberra to uni and it's a beautiful campus. I've just got fabulous memories of the place."

* For more on screenings for the final weekend of the Canberra International Film Festival go to https://ciff.com.au/