The growing number of political memoirs.
You can go for years without a New Zealand political figure writing a book and then, bang, six of them appear in the space of a year.
Each book is highly readable but their differences reflect the political circumstances of the author at the time of writing.
Michael Cullen, was a former Deputy Prime Minister, who died on Thursday after battling cancer; Chris Finlayson is a retired Attorney-General but was better recognised for his work as Treaty Negotiations Minister; Simon Bridges was rejected as leader by the National Party caucus in election year; Sue Kedgley is a retired Green MP but better known for pioneering role in the feminist movement; and law professor Margaret Wilson was the first woman Speaker of Parliament. All had books published this year.
Another, Judith Collins, the current National leader, had a political memoir published in June last year, just 17 days before she was called on to replace Bridges' replacement, Todd Muller.
Leadership ambitions and failure respectively were undoubtedly the driving force behind the books by Collins and Bridges.
The rejection of Bridges clearly had a big impact on his writing style and subject matter in National Identity.
It is a raw and revealing personal memoir with a devil-may-care attitude that suggests he just thought "F**k it - I've got nothing to lose".
The book is peppered with expletives, just as ordinary conversation is with him, and that might be a surprise considering he is the son of a preacher man and with unapologetically conservative values.
As National Party leader, Bridges was a synthesised version of himself. The book is Bridges unplugged. Someone undoubtedly told him to write the way he talks, and he does in a personal, thoughtful and often funny way,
He was lying in Middlemore Hospital, for example, after having had titanium put into a broken jaw and in the adjacent bed was a gang member who'd come off his bike and whose girlfriend apparently kept coming in and shagging him (the gang member) behind the curtains of his bed.
His jaw, by the way, had been broken by a high school contemporary who was furious that Bridges had left the scene of an accident. The assailant's younger brother had driven a Mini through a brick wall in Te Atatū and when the older brother found out that Bridges, a passenger, had bailed, he went to Bridges' home, not far away, and gave him a thumping.
Bailing is not a common theme in Bridges' story. He has a resolute nature.
The surprising disclosure in the book is just how much of an outsider Bridges has felt, as a Westie and a Māori, particularly in the legal world, but one also suspects at times in the National Party.
"I have come to realise I see myself as different, an outsider," he writes. "Being Māori puts me in the minority and yet for much of my life I also haven't felt properly Māori or accepted as such."
The best portrait he paints in the book is not just of himself but of his marriage to Natalie, his half-English, half-Polish, Coventry-raised character of a wife.
By the end, you get a very good sense of why they are so good together and how he gets away with publishing photos of her sleeping with her mouth open.
Two of the six books are by Labour figures, one by a Green and three of them are by National Party figures, which is unusual. There has been a lot more written about and by Labour figures than National, with a great deal of focus on the tumultuous years of the Fourth Labour Government.
All the authors are highly educated with four of them being lawyers, Bridges, Wilson, Finlayson and Collins, and two of them having been academics, Cullen and Wilson.
All the books were written either by retired politicians or politicians in Opposition.
Margaret Wilson's book, Activism, Feminism, Politics and Parliament, was published only last week.
She was raised a conscientious Catholic girl in Morrinsville and you are left wondering one thing: what is about the Waikato that breeds such high-achieving women politicians? As well as Wilson, there has been Helen Clark, Jacinda Ardern and Judith Collins.
Wilson writes well about not just what happened in her childhood but how it shaped her development and what gave her a sense of empathy to outsiders.
She realised later that she had absorbed an Irish form of Catholicism, with disdain and distrust of the English, and its assertion of superiority of the Catholic religion.
"This Irish Catholicism also instilled a deep-seated sense of fellowship with society's outsiders and for just treatment of them."
One of her grandfathers built a movie projector and a shed in which to show movies. Some were homemade but some were hired travel documentaries that stirred a curiosity in the world outside.
She took out books from the local library which, she said "opened my eyes to the world, feeding within me the seeds of anger against injustice that were being planted by my Catholic education."
I remember being somewhat surprised when nobody in Morrinsville seemed concerned about the struggle of the Basque independence movement."
Cullen's book, Labour Saving, was written last year, the same year he received his diagnosis of terminal lung cancer. It reads like a man in hurry to get it finished, without the time to edit it.
But that is good. Too much is better than too little in his case. It would have been unthinkable for such an intellectual historian and colossus of modern New Zealand politics not to have given his take on his life and times in the detail that he has.
There is a significant and valuable contribution by Cullen to the foreshore and seabed issue, what gave rise to it, why he did what he did when he took charge of it and how his preferred solution was not possible when positions became entrenched.
In his final term in government, Cullen went on to become Treaty Negotiations Minister, as were two of the other recent authors, Margaret Wilson and Chris Finlayson – and all three were Attorney-General as well.
Finlayson had more experience in the treaty role and his entire book, He Kupu Taurangi, is about the treaty settlements that occurred on his watch. He and the current National Party appear to have parted ways on some matters - the subtitle of his book is Treaty Settlements and the Future of Aotearoa New Zealand.
Former Prime Minister Jim Bolger spoke at the book launch in Wellington last week and referred to "the nonsense debate some are pushing re the use of another of New Zealand's official languages."
He said it had been a "major mistake" not to more vigorously pursued the teaching of te reo Māori in primary schools when he was Prime Minister because had he done so, a large number of New Zealanders would be familiar and comfortable with the language.
Sue Kedgley's book, Fifty Years a Feminist, is important, not for its section on her life as a Green MP, which covers only one chapter, but as a central figure in the women's liberation movement of the 1960s and 70s.
It follows her transformation from debutante at Mardsen exclusive school for girls to effective feminist who helped get changes on equal pay (also important in Wilson's book), and contraception and raised consciousness.
Unfortunately for former Labour Prime Minister Sir Geoffrey Palmer, she also found an editorial he wrote as Salient editor in 1963 in which he sounded a note of caution to the "new woman" who might drink like a man and choose who she slept with. But such girls, he said, might not find adjustment easy after the last party was over. "What is right for a man may not be forgiven in a woman."
Both Kedgley and Wilson's books are a valuable contribution to the historical record on resistance movements and the New Zealand left.
Judith Collins' book Pull No Punches is a lighter read by comparison, despite its tough-sounding title.
It was published halfway through last year and seemed intent on two key things: showing her back story in preparation for a future run at the National Party leadership and she wanted the last word on the two scandals that had dogged her ministerial career.
The two issues were a private Oravida dinner in China with a Chinese official in 2013 and her forced resignation as a minister during the 2014 election campaign after emails suggested she may have sought to undermine the head of the Serious Fraud Office.
It would not have been wise for her to have had the last word after being cleared and reinstated as a minister in John Key's Government in 2015.
But he was gone by 2016 and while everybody else had forgotten, Collins had not. With spare time in Opposition, she wrote her book.
She felt she had been wronged and let down by Key because she had mentioned the dinner to him before her trip and he had encouraged it.
SIX BOOKS
National Identity – Simon Bridges
•Published by HarperCollins
Activism, Feminism, Politics and Parliament – Margaret Wilson
•Published by Bridget Williams Books
Labour Saving, a Memoir by Michael Cullen
•Published by Allen & Unwin
He Kupu Taurangi, Treaty Settlements and the Future of Aotearoa New Zealand, Chris Finlayson and James Christmas
•Published by Huia
Fifty Years a Feminist by Sue Kedgley
•Published by Massey University Press
Pull No Punches by Judith Collins
•Published by Allen and Unwin
The 19-year-old disappeared without her wallet or mobile phone.