This is the guy who thinks you can get a couple of beers for $7. Who reckons that the impoverished don't drive automobiles. Who actually enjoys the taste of cigars.

And the same guy who suggested this week Australians should pay more for their healthcare costs, because they could live to be a century and a half old.

"It is kind of remarkable that somewhere in the world today, it is highly probable, a child has been born who will live to be 150," Hockey told 3AW's Neil Mitchell.

But while Labor's Bill Shorten popped up immediately to label this a "Sarah Palin moment", it turns out that the Treasurer's comment wasn't so screwy after all.

As University of New South Wales medical faculty dean Peter Smith said, it was no longer "science fiction" to suggest that humans would make 150. Especially considering how much life expectancy has grown in recent decades, changes to lifestyle and diet, as well as scientific advances in the pipeline.

The oldest human on record has already lived to be 122. And they were born in the sickly 1800s – when people thought "going Paleo" meant shacking up with a woolly mammoth. And Pilates was just a European-sounding surname.

Of course, humans have been obsessed with avoiding death and ageing ever since Adam and Eve took a bite of that apple. But the process of living well past 100 – or what is known as "radical life extension" – is now the concern of serious researchers across the fields of medicine, engineering and computer technology.

In labs and research institutes around the world, people are manipulating the genes of roundworms and fruit flies and giving fancy compounds to rhesus monkeys in the aim of boosting the human "healthspan". British researcher Aubrey de Grey says ageing is simply a disease that can be cured.

There is the school of thought that stem cell technology could be used to repair the brain or the heart. Or that weenie little micro machines could be put in our bodies to stop parts wearing out or replace them if they do. It is amazing stuff - if only it could be used to find Julie Bishop's pearl earring.

We take it for granted that all of this is an unequivocally positive thing. Indeed, we stuff ourselves full of vitamins, smother ourselves with anti-ageing potions, join 24-hour gyms and leap on new diet after new diet in the hope that we won't become old geezers.

And every time a really ancient person has a birthday, we scramble to get their advice about how they got there - as if they are some sort of oracle and not simply a genetic anomaly. As Scotland's oldest woman, 109-year-old Jessie Gallan, told us this week, the secret to a long life is eating a "nice warm bowl of porridge every morning" and staying away from men.

Yet when genuinely faced with the idea of living for a really long time, we baulk.

A recent survey by Pew Research found that most Americans actually don't want to live forever. When asked if they wanted medical treatments that slowed the ageing process and allowed the average person to live to at least 120 years, 56 per cent of the 2000 adults surveyed said no. In fact, when asked how long they wanted to live, the median answer was 90. One of the reasons cited was that radically longer life would be "fundamentally unnatural".

And you can understand why. The Treasurer might be worried about the impact long lives would have on the health system, but there are plenty of other reasons why living until 150 is an eye-scrunchingly scary prospect.

For one thing, who wants to work for more than 100 years? You can Pollyanna it all you like – and imagine the many different careers you could explore in that time. But in practice, the thought of a century's worth of turning up to work five days a week is not cool. Neither is the need to requalify as a hairdresser, forensic accountant or marine biologist every few decades, just to keep yourself awake.

If people are freaked out about waiting until 70 for the age pension, they are not going to like waiting until they are 140.

Then you get to love.

We have trouble enough staying married to the one person for the 50 or so years that spans the current grown-up human life span. How hard would the romance die and the conversation wither if we were looking at 120 or so years of marital bliss?

Even if instead we had several marriages – like careers – that could equate to three or four epic break-ups and three or four epic exes. The only people that win in this scenario are alcohol vendors, shrinks and divorce lawyers.

There are also the generational issues. As Pew's David Masci asks, "In a world where people may not look or act much older than their parents, grandparents and even great-grandparents, would relationships remain the same?"

As unappealing as it is to have great-grandma borrowing your clothes or turning up in the same bars as you, it is more worrying to think about what this means for the property market. With so many super-old people hanging around, how will any young person possibly be able to buy their own place?

Apart from anything else, 150 years is just a really, really long time to be doing tax returns, the washing up and trying not to smoke. It's not extending life, but adding a whole new one on.

And that, Methuselah, sounds like way too much hard work.

Judith Ireland is a Fairfax Media journalist.