He isn't one to get ahead of himself, which is why this week he was wary about talking up the Crusaders' chances against the Sharks in Christchurch tonight, saying simply the team had prepared well over the past fortnight and it was now up to them to get the job done to make their first Super Rugby final since 2011.
But he was in the mood for some reflection, including on his arrival at the Crusaders in 2002, his respect for his rival du Plessis, and the things he will miss most in Christchurch.
Asked if after the fifth broken arm he might have considered a new career, he replied: "Never. You wonder why injuries are happening, but it allows you to get a bit of mental resolve and I think it's been the making of me in terms of being able to handle injuries or non-selection or stuff like that.
"It gives you the resolve to keep boxing on. We're pretty lucky to be doing what we're doing."
Flynn arrived in Christchurch as a 21-year-old not knowing what to expect after representing Southland for two years.
They did things the old-fashioned way in Invercargill in those days - young players had to scrap for everything - so his arrival at Crusaders' HQ was eye-opening on a number of levels as front rowers Greg Somerville, Greg Feek, Mark Hammett and Dave Hewett took him under their collective wing.
"As soon as I came to the Crusaders I found it quite unsettling in terms of how much they were prepared to help me. I had come from an environment where you learn by getting a hiding and then all of a sudden I was then given all this knowledge ... I was like 'what's the story here, what's the catch?'. It's always been like that since I've been here."
Flynn's experience is probably the main reason he has been given the starting hooker's role against the Sharks, and he has nothing but praise for 30-year-old du Plessis.
"He's a pretty fierce competitor, he's been one of the best in the world for a couple of years and he's also come back from a pretty serious neck injury so that deserves respect in itself," Flynn said.
"As a footy player and as someone who thrives on challenges, it's pretty exciting to come up against the best and that's what you mark yourself on."
Flynn has always been a forthright character, one who is prepared to ask difficult questions if they are required, but he also has a finely honed sense of fun.
One of things he will miss when he leaves for France - and with the competition starting in mid-August, Toulouse want him there as soon as possible - is the annual "spud competition" which has been a tradition for the past five years or so for Flynn and several of his mates, including teammate Dan Carter.
The competitor who grows the most potatoes from a single plant takes the title. It is a social competition in which Flynn has yet to excel.
"I'll definitely miss that. I think the boys are holding a spot for me, they're not going to just give it to anyone while I'm away.
"I have been horrible for the five years. I needed this year for a bit of redemption, but it will have to wait.
"DC [Carter] is terrible as well. I think putting so much focus on the footy means spud-growing definitely takes a bit of a hit."
