Tech entrepreneur Ruslan Kogan works 80 to 100 hours a week.
"I work 24 hours a day with a few breaks in between," he says.
"The good thing is I absolutely love what I'm doing. So when people say to me 'how many hours a week do you work?' I tell them I don't work any hours a week - I live this stuff."
Kogan, the founder of Australian online retailer kogan, which is worth A$315 million according to BRW, attributes his strong work ethic to his parents, who migrated with him from Russia in 1989 with A$90 in their pockets.
His father, a qualified engineer in Russia, worked at Melbourne's Queen Victoria Market, drove taxis and delivered pizzas, all while learning English and trying to spend time with his family.
His mother worked as a waitress, a cleaner and at other jobs.
"At a young age, having seen all my parents do all of that has played a significant part in my work ethic right now," says Kogan, 31.
"My dad had his 60th birthday last year and is proud that he has not once been late to work and never taken a sick day."
Kogan is not alone among hard workers in believing he's inherited his work ethic from his parents, and research to be published next year has confirmed that - up to a point.
A study by researchers at the University of Michigan found that people inherit their work ethic (or lack of one) from their father, but not their mother.
They found that the orientations of their parents play a stronger role than other forces such as religion, personality or profession in determining how hard a person is likely to work.
People who perceive their father to have a strong career-orientation are more likely to be career-oriented themselves - but career-determined mothers have no effect on their kids' work orientation.
The researchers suggested their work might have been skewed by the fact that many of the survey participants grew up in the 1980s, a time when women were less well represented in the workforce.
But the finding has been rejected by a lot of Australian hard workers. "I inherited my work ethic from my mum," says Elisa Limburg, who runs events and marketing company, elevents.
"My mother was an accountant who later owned her business, mainly in bookkeeping. She had a stronger personality than my father with a lot of energy, which helped her push through and just do things. My mother wouldn't stop until a task was done, and she was always busy doing things."
Nearly 14 per cent of Australian employees work 50 hours or more a week, according to the OECD (Organisation for Economic Co-operation and Development), much higher than the OECD average of 9 per cent.
Some 21 per cent of men work very long hours compared with just 6 per cent for women. Against this is balanced a higher proportion of people - mostly women - who work part time than in other economies.
Professor Barbara Pocock from the University of South Australia's centre for work + life says Australians also think they work harder. Around 30 to 40 per cent of Australians say they are working intensively, with tight deadlines and work overload.
Small-business owners, in particular, work hard.
"There are other rewards from running your own business, but long hours are definitely a consequence," says Pocock.
"You'll often be doing quite extended hours with negative consequences for you and your family as well."
Nonetheless, many small-business owners enjoy working long hours. Dean Salakas, who runs the party supply shop thePartyPeople.com.au, works "huge hours" - at home at night, on Saturdays and sometimes on Sundays as well.
He says he inherited his work ethic from his mother, who initially started working as a clown, before employing a stable of clowns and eventually opening up a party supplies shop.
Salakas, 31, says he spent time at the shop with his mother instead of going to day care, and worked from a very young age, shovelling sand into bags to weigh down balloon displays at A5c each.
"When I was at high school people would say it was a bummer that I had to work on weekends for my parents, but that's normal for me," he says. "For me working six days is normal."
While Kogan has always attributed his work ethic to his parents, he used to think his entrepreneurial drive and skills came from somewhere else.
But he changed his mind at an entrepreneur awards night when he told the audience that his parents came from communist Russia and didn't pass on any business skills to him. But an elderly man in the audience told him: "Think about what it takes to be an entrepreneur: You've got to drop everything you've got, take a massive risk, travel into the unknown and work your arse off for a potential benefit that might not be there."
Kogan recalls: "Then he said to me 'Think about what your parents did as immigrants when they fled Russia' - and it's exactly that.
"It made me realise that I got a lot more business skills from my parents than I ever thought, even though they've never run a business."
- Sydney Morning Herald