He was to study poverty, understand poverty and fight poverty.
Although his bachelor's degree was heavily slanted towards mathematics, he went on to study history and his doctoral thesis was on economic and social history focusing on poverty in late 19th century London.
He became a minister in the second term of the Lange Government with associate finance and social welfare responsibilities.
In 1991, after the fourth Labour Government effectively fell apart, Michael held his seat and set about rebuilding a post-Rogernomics Labour Party which was to win in 1999 with him as deputy leader of the party and finance minister.
It was during the following three terms of government I was closest to Michael, but only in the sense that I sat adjacent to, or beside him, at Caucus meetings, the first half of which he chaired.
Though he was a ferocious debater and could rip an opposition apart on his day, he struck me as fundamentally shy and at times self-doubting.
I did not know him well and I think few did, beyond the family he doted on.
There were difficult and divisive issues during this period, but he was the always reasonable and creative glue that helped to hold the Caucus together.
I carefully noted what he was reading, and it was this habit that caused me to subscribe to The Economist and read Thomas Piketty's Capital in the Twenty-First Century, an influential work which explored the origins of inequality.
A few weeks ago, Sir Michael Cullen was asked to identify his proudest achievement and he replied that on his watch inequality in this country was reduced.
His major achievements did just that, are far sighted, affect millions of Kiwis and survived a subsequent National Government.
These included Working for Families, a tax credit system which puts extra cash in the hands of lower income families bringing up children. This was a classic example of the redistribution of wealth that Thomas Piketty advocates to combat inequality.
So is KiwiSaver, the state subsidised retirement savings programme that in June last year had just over three million participants. With house prices exploding since Michael Cullen's time in office, many KiwiSaver account holders may well get to own their first house with their KiwiSaver money at retirement.
It was typical of him to focus on the next generations, and I recall a speech he gave at a party conference in the 90s where he said that by far the very best investment in the future was education. On his watch solo parents were funded into education with immense ongoing benefits to my own whānau and the country's finances.
The New Zealand Superannuation Fund, known universally as the "Cullen Fund", is yet another example of Michael's foresight. This is a sovereign wealth fund now standing at close to $50 billion and is aimed to cover a shortfall in pension payments over coming decades.
Although climate change was hardly emerging as an issue when Michael was our minister of finance, his move to re-nationalise our rail system and consolidate it into KiwiRail, meant that New Zealand now has the option of a carbon emission-free freight and passenger system which still covers much of the country.
To the great credit of Jacinda Ardern, Grant Robertson and the Labour Government, this golden opportunity has not been lost.
I think that Sir Michael Cullen's greatest legacy, with Helen Clark, was to rebuild a Labour Party that refined and defined a philosophy of social democracy suited to the 21st century and very attractive to new generations of Kiwis.
They provided the intellectual foundations, shaken by the era of neo-liberalism, which resulted in the tsunami of talent that graces the benches in Parliament now occupied by Labour MPs.
Mike Williams grew up in Hawke's Bay. He is chief executive of the NZ Howard League and a former Labour Party president. All opinions are his and not those of Hawke's Bay Today
