OPINION: Remember John Key? He was once our prime minister.
Actually, he was our prime minister for slightly more than eight years – in other words, nearly three terms.
That's quite a long tenure. If you rank all our prime ministers according to their total term in office, he's in eighth place – slightly behind Helen Clark and Robert Muldoon, but ahead of Jim Bolger and well in front of David Lange.
And I can't resist pointing out that if this were Australia, where politics is a lot more volatile, Key's eight years-plus would place him up there with tenacious survivors like the late Bob Hawke and John Howard.
Key resigned as prime minister only 2½ years ago. It may come as a surprise to be reminded that it was so recent, because to all intents and purposes he has since vanished from public view. It's almost as if he never existed.
Remember, this is a man who was regarded as something of a political colossus – in New Zealand terms, anyway – when he was in power. His personal approval ratings surpassed even those of Jacinda Ardern post-Christchurch.
Press gallery veterans considered him the consummate politician, with an almost mystical power to charm voters. Caucus unrest was almost unheard of when Key ran the show.
Yet now his name is hardly spoken. Have we got short memories, or is there something else going on here?
Admittedly, Key departed in unusual circumstances – that is to say, he went of his own accord, at a time of his choosing. That's rare in politics, where most leaders end up outstaying their welcome and refuse to leave the stage even when it's obvious to everyone else that their time is up.
Muldoon, for example, remained a baleful, cantankerous presence around Parliament after he was rolled as National Party leader. And although Lange resigned as prime minister of his own accord, he too remained in politics and metamorphosed from the witty and charismatic leader of the fourth Labour Government to an increasingly bitter, disenchanted and physically unwell figure in opposition.
But with Key, you got the feeling he'd ticked being prime minister off his to-do list and was happy to move on.
All of which raises an intriguing question: 50 years hence, which New Zealand prime ministers will historians rate as the ones who made the most lasting impact?
My prediction, for what it's worth, is that for all his personal popularity when he was in power, Key's name will be well down the list. Because when you look at what he stood for and what he achieved, it didn't add up to much.
He was a manager and a pragmatist rather than a visionary, and although he managed competently enough – he helped get us through the global financial crisis, after all – we really knew no more about his values and aspirations at the end of his term in office than we did at the start.
To this day I don't know what motivated Key to enter politics in the first place.
His one serious attempt at creating a legacy – the referendum to change the flag – ended in ignominious defeat.
There's a marked contrast here with Norman Kirk, who died in office 45 years ago. Kirk lasted less than one term, but his name endures, and not just in the memories of ageing Labour supporters.
Kirk is remembered because he was seen as a man with emphatic political values. Even in his brief term in office, he presided over a lasting reset of New Zealand's place in the world. By asserting our right to make our own way, rather than function as appendages of Britain and the United States, he changed the way we saw ourselves.
To use a fashionable term, he was a conviction politician. He got into politics because he had firm views about the need for change, and he had the ambition and energy to make it happen.
Lange was a conviction politician too, as was Helen Clark. You knew what they stood for even if you didn't agree with them. Ardern seems to have been cut from similar cloth.
National's leaders, on the other hand, have tended to fall into the manager-pragmatist category. Keith Holyoake, Bolger and Key did whatever worked and were largely unencumbered by ideology. An exception was Muldoon, who had very strong convictions, but often seemed to be in the wrong party.
Which prime ministers left the deepest footprint? I think the answer is clear. We still talk about Muldoon and Kirk, and Clark remains influential.
That's not to say they were our greatest leaders, but I suspect they're the names New Zealanders are likely to remember when Key has been relegated to the back pages of history.
Karl Du Fresne is a Stuff columnist