Cullen famously sorted out the country's financial future by introducing the KiwiSaver scheme and starting the NZ Superannuation fund - dubbed the Cullen fund.
He's certainly careful with money.
If anything, his reflections on living it up as deputy Prime Minister are even more revealing of his conservative approach to spending.
Back then he would splash out on a $35 bottle, he recalls, but the quality of $15 bottle is now much improved.
Cullen is battling stage four cancer, but it hasn't dulled his wit or intellect.
He's working on a book and shares some of his personal stories with Liam Dann in Episode 2 of the Money Talks Podcast (click link below).
Cullen remembers his first job at a tobacconist on Cathedral Square.
"Not that I'd want to admit that to Helen [Clark]," he says with a smile.
With a doctorate of history, Cullen has a rare ability to see his life in the context of the social and economic forces that shaped it.
He recalls his childhood move from post-war England to a new suburb in Christchurch backing on to a market garden where "it seemed pretty primitive by North London standards with a chemical toilet ... and it didn't have a mains water supply".
Another difference was that, in 1995, wages in New Zealand were still higher than they were in Britain.
So his father was actually paid more, even though he couldn't carry on his trade, and the family was nominally better off.
But it was very much a working-class upbringing, instilling a cautious attitude to finance.
Michael Cullen, former Finance Minister of the Labour Government between 1999 and 2008, talks to Liam Dann via Zoom in December 2020.
"I've been a very conservative saver. I've never ventured outside the bank," he says.
"For the first time in my life I'm thinking, good God, at 0.3 per cent interest on my main deposit in the bank - take off tax and even with low inflation I'm going backwards."
If Cullen has had one obvious indulgence, it has been his car.
"I have a Jag - a three-year-old XF - because I was doing a lot of long-distance driving. I wanted something comfortable and big so I could do that journey and I wouldn't feel completely knackered at the end of it," he says.
"But now I think maybe this is a bit large and pretentious for driving into town in Whakatāne, maybe it's time I downsized."
Covid put paid to travel plans this year and with a compromised immune system, he's narrowing his focus a bit.
But he says he still feels privileged and grateful for the life he has, with four children all living in New Zealand and within driving distance.
Money Talks is a new podcast series. It isn't about personal finance and isn't about economics, its just well-known New Zealanders talking about money and sharing some stories about the impact it's had on their lives and how it has shaped them.
Liam Dann, NZ Herald business editor at large. Photo / Sylvie Whinray
Listen to the full interview on the Money Talks podcast. You can find new episodes in the Herald, or subscribe on iHeart Radio
