When Gai Dudley finished paid work in 2008 there was one word she was keen to banish from her vocabulary - retirement.

It was a word, the former school teacher says, that "makes it sound like you're being put out to pasture".

"That was something I certainly wasn't ready for," Ms Dudley says.

A lover of art, she signed on as a volunteer at the Art Gallery of South Australia, becoming one of the six million Australians who give their time for free to groups and organisations across the country.

The work of Ms Dudley and all of Australia's unpaid workforce will be celebrated during National Volunteer Week, Australia’s largest annual celebration of volunteering, held from 19-25 May.

This special event highlights the important role of volunteers in our community and invites people not currently volunteering to give it a go.

Ms Dudley's volunteering journey started back in 2008, and she is still happily volunteering at the North Terrace institution, mostly on the front desk as a greeter. She has also done stints as a guide, showing visitors through the gallery's extensive collections.

As a former teacher Ms Dudley naturally gravitated towards guiding school groups and young people, and says she gets a lot out of introducing children to the world of art.

"One of the things I used to love asking kids, especially younger kids of about eight or nine, was, 'do you know who owns all of this stuff?" she says.

"You would get varying replies - some kids thought that the Queen owned it all. And I would say to them, 'no, it's not the Queen at all. I own all of this. And so do you. And you do too. In fact, everyone in South Australia owns all of this art."

Ms Dudley says she enjoys sharing some of her favourite works in the eclectic gallery, including Australian artist Tom Roberts' classic 1891 painting A Break Away! - juxtaposed next to a small bronze by famous French sculptor Auguste Rodin - and JW Waterhouse's Circe Invidiosa (pictured), a haunting image of a scorned witch poisoning the sea.

"If you take a tour with a guide, you get a sense of just how eclectic the gallery's collection really is," she says.

"For example, things are deliberately not in chronological order - if you go into the Australian Wing you'll find contemporary works right next to some of the oldest Australian paintings you'll find anywhere.

"The curators like to keep people guessing. The Rodin next to A Break Away! - I like to ask people, 'why do you think they've put these two things together?'.

"And when people look closely, they can see that there's actually a clear visual connection between the two works.

"I remember years ago speaking to an older lady who was sitting in the vestibule waiting for her family. She told me she loved the new hang and when I asked her what she liked about she said, 'I love that it's so mixed up - it really makes you think'. And that's the whole point, isn't it?"

Ms Dudley says her current role as a front of house "meet and greet" volunteer was "my favourite thing I've ever done at the Gallery".

"We get to meet people every day who come from all around the world," she says.

"We've started keeping a list of where all our visitors come from. The other day we had a visitor from Yemen.

"I get a lot of stimulation from volunteering at the gallery.

"I've made a lot of friends other volunteers, the front of house staff, who are fabulous, the curators and, especially, the security people who we work very closely with.

"The security people have an incredible amount of knowledge about the gallery and the art."

Ms Dudley's advice for anyone thinking about taking on a volunteering role? Just do it.

"I know people who volunteer at the Botanic Garden, at Carrick Hill, at the Hans Heysen Ceders gallery, and it's just such an interesting thing to do," she says.

"You learn so much and you get to meet so many wonderful people."

Ms Dudley is one of around 200 volunteers who generously give their time and expertise to enhance the experience of visitors and assist the work of staff at AGSA in areas including front of house, public programs (including as gallery guides), image services, library, curatorial and registration.

For more information about volunteering at AGSA. click here (external site).

For more information on National Volunteer Week - which runs from May 19 to 25 - click here (external site).