John Key says the decision to step down is the "hardest decision [he's] ever made" and says he's proud of what he's achieved in his time as Prime Minister.
"This has been the hardest decision I've ever made and I don't know what I'll do next. But for me, this feels the right time to go," he says.
"I'm very proud of what we've achieved in terms of trying to help vulnerable New Zealanders," he says.
"Whether it's been the Christchurch earthquakes or more recently Kaikōura... I think with Pike River, the Rena, the global financial crisis, there's been a lot of things there."
As for regrets, he's had a few, like the failed Trans-Pacific Partnership (TPP) and not getting to change the flag.
"There was a new 'New Zealandness' about it, and if I had my time again maybe I would have pushed it harder at the end."
It was a shock resignation to end all shock resignations and family was a big part of the big call.
"My daughter, Stephie, and my son, Max, have transitioned from teenagers to young adults while coping with extraordinary amounts of intrusion and pressure because of their father's job," Mr Key says.
The decision was made back in September, while he was at the United Nations General Assembly.
While in New York he had to dodge questions about whether he would stay on, something he didn't enjoy doing. He realised he couldn't keep it up.
"One of the things I said to [wife] Bronagh on the way home was, 'Look, I just don't feel comfortable looking down the barrel of the camera and not being honest.'"
Mr Key gave a clear nod to Deputy Prime Minister Bill English as his successor, even though Mr English hasn't yet put his hand up for the job.
As for his legacy, Mr Key cited economic management.
"We're strong. We're in surplus. We're growing; we're creating jobs. We're doing well," he says.
Being forced to work with New Zealand First leader Winston Peters was looming as a problem, although he claims it wasn't.
But on Monday there was a moment in New Zealand politics that will bring colossal change, with Mr Key calling it himself, "the end".