It is fair to say that no one was expecting John Key to announce his resignation yesterday.
There had been some talk over the past few weeks that while Mr Key would probably take the National Party to a fourth term of government next year, he would have stepped down midway through the cycle.
But, yesterday's announcement was nothing short of a bombshell.
It immediately raised the question of why? There are many theories going around and one, or more of them, may even turn out to have some truth to it. Almost certainly there was family pressure.
But if you look at it, in hindsight it does make sense. Mr Key made millions as a trader and those instincts allowed him to successfully use a brand of practical populism in his political career.
Unencumbered by the baggage of a political ideology, he was quite willing to read the mood of the nation and tailor policy accordingly. This allowed him to keep his ratings up longer than usual.
Going out on top would have been important to him and by springing such a surprise, he was always going to be in control of the process.
The thing with Mr Key is that he was never a loyal National Party foot soldier and basically parachuted into Parliament with the express intention of becoming prime minister. This means that he was always going to do things on his own terms.
He probably feels that he built his legacy and it is now someone else's turn. Whether that is Bill English or not remains to be seen. The knives will be sharpening given his leadership history.
Who knows, maybe in the wake of Brexit and Donald Trump, Winston Peters could become the next prime minister.
Anything is possible these days.