"It is not going to change the world and there are many things we did, from the Christchurch earthquakes to economic issues that we dealt with, but that is the one I feel I definitely failed on," he said.
"I suppose I also have to take responsibility and say, well look, maybe there were some other things I could have done. To be frank, I think I should have just pushed it even harder."
Sir John said Kiwis were typically more reserved than citizens of places like the United States.
"Americans use the flag to symbolise what they believe, which is that America is the greatest country in the world," he said.
Sir John spoke about how his father died when he was 6, and how his mother raised him in very poor circumstances.
"She was an Austrian-Jewish refugee who got out just before the Nazis invaded in 1938," he said.
"My mother was a very determined Jewish matriarchal woman. She always used to say, 'You get out of life what you put into it'."
His advice to people, especially the younger ones, was that if they wanted to do something then they had to make it happen.
"I wanted to be prime minister, I wanted to be financially successful, I wanted a successful marriage," Sir John said.
"A lot of times the reason people don't act is the fear of failure; they are worried about what other people will think if they don't quite make it. I say to people, 'Just back yourself'.
"In the end, I would rather give it a go and fail then sit back and be a Monday morning quarterback critiquing everyone else."
