In an extreme manifestation of butterfly theory, Tony Parsons blames Fifty Shades of Grey for changing his life.
British author and journalist Parsons had created and exploited a novelistic niche - "man-lit"- built on his surprise international hit Man and Boy.
But the last of the sequence, Catching the Sun, tanked - among many books, he believes, swamped by the Fifty Shades phenomena. "A lot of careers were completely destroyed by that book, because it completely dominated the industry," he says.
He needed a new idea. So he cashed in his pension, and inspired by a chance conversation with movie director Sam Mendes, decided to try his hand at crime fiction.
"It was scary," Parsons says on the phone from London.
"You're not just gambling with your own future, but your family's future. It would have been disastrous for me if it hadn't worked.
"There wasn't a plan B, that was the scary thing; and I always prefer to have a plan B, C and D. I'm too old and too experienced to think the world owed me a living or couldn't get along very well without me. I was stepping into a very competitive part of the market and I knew it had to be good. I knew I had only one shot . . . "
Parsons' gamble was swiftly repaid. Shown the manuscript of The Murder Bag, publishers Random House immediately offered a three-book deal.
The Murder Bag topped the British bestseller's list. And he turned down a television deal, in the hope that he would instead sell the film rights.
So he can reflect cheerily on Catching the Sun's failure.
"It had run its course, and in a way, it was quite good that it was a brutal failure...it was a bucket of cold water thrown right in my cakehole which said ‘it's time to change, or jack it in'," says Parsons. At 60, he says, he had no desire to retire - and he had a wife and 11-year-old daughter to support.
British audiences knew Parsons as a former New Musical Express journalist, ex-husband of media commentator Julie Burchill and a vitriolic and very well-paid Daily Mirror columnist (parodied as Tony Parsehole in Viz magazine).
"People can assume if you have a level of success it goes on forever - but it doesn't," he says.
International readers would more likely have remembered Man and Boy, a counterbalance to the chick-lit movement that told the emotional tale of a single father and his son, written when he was "very raw" after his mother's death.
Those novels drew heavily on Parsons' own life - he raised his son solo after splitting with Burchill - and there's echoes of that again with the The Murder Bag, which overcomes a clichéd and unlikely opening to find its feet and become a rather gripping read. His hero, Detective Constable Max Wolfe, is a single father (tick), who boxes with a trainer named Fred (tick) and owns a dog called Stan (tick).
He says he thought deeply about Wolfe for a year. He knew other heroes such as James Bond were 'undomesticated "men alone"' but he wanted something different: so being a single dad gave Wolfe a foundation but also the freedom to pursue women. "You do play to your strengths and you work out a world you can relate to," he says.
He also talks with ambition of how great crime writers created characters such as Bond and Sherlock Holmes "who can be rebooted by different generations and reinterpreted" and wanted Wolfe to have the same potential.
Yes, he was bold about The Murder Bag: Parsons declared a desire to be bigger than John Grisham, and secured a jacket endorsement from Lee Child.
"You can't do it apologetically," he explains.
"You can't do it half-heartedly. And you can't do it bashfully. I entered the arena with all appropriate humility, I wasn't bigging myself up. But you can't be apologetic: this is a bottom-line business. Every week my publisher tells me to the physical copy how many books I have sold."
Despite this bravado, Parsons says he's a changed man.
In a recent Guardian interview, he reflected: "what a dick I was" in his more controversial years.
He says the Guardian were "ridiculous" in trying to skewer him with ancient quotes from his columns, but concedes: "I think time knocks the cockiness out of us. And I was probably more cocky than most and needed more of it knocking out of me. I do think I am a changed man. But at the same time, when they push me about what I said about Simon Le Bon's bum in 1983, they push me to a point where I think 'I don't regret it at all. I'm glad I said it'."
Partly to promote his book - playing on Wolfe's amateur pugilism - Parsons has just fronted a BBC documentary/love-letter to the noble art which screens here next weekend.
It offers a cultural view of boxing, complete with the usual litany of famous aficionados (Hemingway, Mailer, Joyce Carol Oates, Picasso) in which our man comes painfully close to comparing himself with Hemingway.
Boxing, he says, "gives you what you need", whether it's courage, fitness, or in his case, the longevity to see his daughter grow up and chase off any teenage suitors. He's amazed, he says, that the BBC let him make it.
Parsons still has the capacity to cause ripples in England - the latest by announcing he will vote for the nationalistic UKIP party in their forthcoming elections.
Most UKIP voters appear to be xenophobic little-Englanders, but Parsons essays a long explanation about how his will be a protest vote in favour of Britain opening its borders not to anyone from Europe, as it does now, but good people from Japan, America, India, Australia and in particular, his daughter's brilliant Kiwi primary schoolteacher who wanted to stay, but couldn't.
Of course, he says, the Guardian didn't let him explain all this, "it was just 'he's a bad boy, he's been naughty again. Let's get him on the naughty step'."
Actually, says Parsons, whose books all seem to yearn for the glorious England of days past, while he's still a proud Londoner, he wouldn't mind emigrating . . . here. New Zealand, he says, seems "a very confident country with an incredible sense of who you are", while broken Britain is disconnected from the "shallow men" who attempt to lead it.
This time, David Cameron rather than softcore erotica may be the motivation, but he's shown he's game enough to make another life-changing decision.
The Murder Bag, by Tony Parsons, Random House, $30, is out now.
The Culture Show: Tony Parsons - The Art of Boxing screens on BBC World News, Sky channel 89, on Saturday June 28 at 4.30pm and repeats Sunday 29th at 10.30am and 10.30pm.
- Sunday Star Times