"I rowed in summer to be really fit for winter and that taught me the mental toughness and training I needed if I wanted to do well in this work," he recalled.
Flynn was not the most dedicated student at Southland Boys High. He and the staff clashed quite a bit but never about sport, where the teenager excelled.
He had found his niche but he had to channel his behaviour to fit his career choice.
Strong work attracted the Crusaders scouts and 11 seasons ago Flynn shifted to his new franchise.
"I consider it a privilege to be here, it is living the dream playing rugby for the Crusaders."
When that bubble comes to a close Flynn will have to find some other career to absorb his time.
He believes he has a few seasons left, perhaps even another tilt at the 2015 World Cup and he has not given away hopes of an All Black recall after feeling that rejection this year.
"I have got a few things in the pipeline, some investments to help me with a passive income and ideas about a few things I could do.
"To play footy and then be in Struggle Street would be tough but only the elite players seem to get the elite jobs," he said.
Flynn would love to be back in black but his focus is on the Crusaders' campaign and rewards which may flow from there.
In Christchurch tonight he will moor the frontrow of an impressive pack which is hunting a continuing role in the playoffs.
The Crusaders pack has wrought regular damage this season although the backs have not always made that advantage pay.
Flynn does not see the Bulls drifting far from their usual attritional style.
"They will be strong up front, they have some very powerful ball runners and Francois Hougaard and Morne Steyn, if you give them a chance and they have enough ball, they will run a game."
His opposite, Chiliboy Ralepelle, was an athletic contributor who had taken over the hooking role from the equally competitive Gary Botha.
The Bulls have lost the onfield lineout contributions of Victor Matfield and Bakkies Botha this season although Matfield remains a lineout consultant for the team's new ball winners, Juandre Kruger and Flip van der Merwe.
Flynn is not twitchy about this area of the contest.
"If we get all of our own ball then we will be okay," he said.
"Our lineout is not as strong as our scrum but as long as I put the ball on the mark we'll be right.
"Our scrum has been a real strength," he said.
"How is that? We are not the biggest pack but we have done a lot of work in this area, we are technically sound and drive well as an eight."
The days of setting 50 or 100 scrums at training during a week were gone.
The Crusaders spent plenty of time analysing that part of their work so they were tuned in for the crouch, touch, pause commands, Flynn said.
"I would not have lasted 11 seasons if we had done the scrum work of old but now I can see myself getting through a few more."
