It was roundly denied at the time, but as the months slip by there is a growing acceptance from some of Ireland's large touring contingent that the Lions Hangover was probably a real thing.
They may well have been denying it sincerely at the time, and trying to convince themselves that they were running at full match sharpness. Now that they’re into the heart of the season, they’re remembering what full match sharpness is supposed to feel like.
Jack Conan, for example, went straight into a Test match against the All Blacks for his first outing of the season, having missed out on URC gametime with Leinster due to a knee injury.
"As much as I was trying to tell myself, 'I'm ready, I've trained well for the few weeks leading up to it’, it's very difficult to go and have no game time and then straight to the internationals," he said, admitting he wasn’t pleased with his November form for Ireland.
"On a personal level, I probably felt mentally just not as sharp as I could have been.
"I was disappointed in how I performed in some of those, not entirety of games, but moments within the game. Things I backed myself on probably weren't at the level they need to be for this group. That was disappointing on a personal level."
Confident in his own skin and an articulate, honest speaker, Conan (above) has always come across as one of the most relaxed personalities in the Irish squad.
But behind the scenes in November, he was struggling to clear his mind.
"In November, I felt stressed," he adds.
"We talk about having the capacity to perform. I felt like I didn't have that mentally. I probably was just getting a little bit… not doubting myself, but just kind of external thoughts and things outside of rugby affected me a little bit.
"So, I didn't feel like mentally I had the capacity to perform to my best level because I was probably a bit full, you know what I mean, didn't let things happen, didn't have the calmness I needed to have to perform.
"It still comes and goes. At the moment I feel good, I feel much fit, my body feels good, and I’m just trying to stay calm, enjoy it, be where your feet are, don't think about anything other than the moment in front of you."
Part of the reason the Bray native is usually so chipper is that he’s having a career he never expected to have.
While he made his Ireland debut more than 10 years ago now, the early years of his career saw him deep in the queue for gametime in the Irish back row.
Reflecting on two Lions tours and 55 caps, he feels like he’s playing with house money.
"Years ago, it was 2016 or 2017 and I was talking to a mate of mine and he was like, ‘If you retired in 10 years' time, how many Ireland caps do you think you'd be happy with?’.
"I was like, ‘Jeez, if I got 20 caps it'd be unbelievable’ because I think at that stage I'd probably had two or three maybe. Do you know what I mean?
"I'd been in and out of camp for years but I'd never been, not a mainstay, but I hadn't probably taken my opportunities well enough and I hadn't been there consistently week-in, week-out, so fast-forward a few years and I've played 55 times for Ireland is unbelievably special.
"Playing for the Lions is great and it's not something I ever thought I'd do, but if I was given the opportunity, if I had to pick playing for Ireland or making the Lions tour, it's playing for Ireland.
"It's the greatest joy, I think, for everyone to be part of this group. It's an incredible honour to play for the Lions, but for me, playing for Ireland, it doesn't get any better than that. It's the thing you grew up thinking about, wanting."
If his patient wait to break into the Ireland team is making him grateful, the standard of back rows breathing down his neck is keeping him motivated.
"I always feel I have a lot to prove every time I come in.
"Young lads coming up. You see Bryn Ward training there today. He's been great, he's like a duck to water out there.
"Obviously, lads injured at home who can't be here, or other young lads. You look at Brian Gleeson, James McNabney up north, who's injured and hopefully back soon in the next couple of weeks. Great players.
"When you get a bit older, you can never take it for granted because there's always that cohort of lads that are coming behind you.
"If you don't make the most of it, there's always someone waiting in the wings."
And while that "cohort" of young players will one day take the jersey from Conan, he says there’s a responsibility to help them upskill.
"I was fortunate when I was coming through that there was older lads there that would have helped you out.
"I probably was guilty of not going to them enough to ask them about things, so as you get to be a bit of an elder statesman, you're conscious that young lads mightn't feel overly comfortable coming and asking.
"But if you go up to them and be like, ‘How are you, anything you can't wrap your head around or what are you struggling with or how can I help?’ This group is unbelievably good at doing that.
"You try to look after the young lads as much as you can, but they're well able. They're not, they're not slouches and they're good players and they wouldn't be here if they weren't."
For now, the Leinster veteran has no plans to hand the jersey over, or give it up without a fight in this Six Nations.
Andy Farrell’s side will leave their Portugal training camp tomorrow to catch a flight to Paris, ahead of Thursday night’s opener away to France.
Ireland had a record win away to the French two years ago in Marseille, but were overpowered at the Aviva last March, going down 42-27.
"I think more than anything else, it was just the physicality," Conan says, of that defeat.
"A lot of the one-on-one collisions, just giving them easy metres. We know they want to keep the ball alive and if you aren't winning collisions, it's very easy to throw it offloads and things like that.
"You're not getting any time in the tackle. You're not getting a point of reference for your defensive setup to actually get up off the line.
"If you let them get over the gain line and you're missing collisions or you're a bit slow and they're on the front foot, you're constantly backtracking and it's very difficult to get off and shut them off.
"We haven't spoken about it yet, but I know the lads who played last year will obviously have that fresh in their mind."
Follow every Ireland game in the Guinness Six Nations on RTÉ.ie/Sport and the RTÉ News app, or listen to live commentary on RTÉ Radio 1.
Watch live coverage of England v Ireland (21 February) and Ireland v Wales (6 March) on RTÉ2 and RTÉ Player.
