He doesn't wish to call it regret, but, Donncha O'Callaghan doesn't hide from the fact that he knows he ought to have won more throughout his career.
Although still going strong at 38-years of age with Worcester Warriors of the English Premiership, O'Callaghan can't but look backward and wonder 'what if?'
Having taken some time to realise how good a team he was part of with Munster throughout the previous decade, a Heineken Cup semi-final defeat to Leinster in 2009 inadvertently put those years of collective progression to rest:
At the time, maybe I'm delusional, but we were a better team that season than we were in previous years. On that day, [Leinster] deserved that victory ... but I think we played some of our best rugby that year and we didn't perform on the day.
And actually, it led to a chain reaction of us loosening our grip on stuff ... one poor 80 minutes has repercussions for the rest of your career and it's a scar.
After securing European success in 2006 and 2008, that defeat in '09 allowed a changing of the guard in provincial Irish rugby - Leinster going on from that semi-final victory to win 3 of the next 4 European Cups.
Speaking to Sky Sports, O'Callaghan asserts now that the "game certainly shifted momentum. It was a killer."
Despite plugging on with his career beyond what many would deem possible, O'Callaghan's outlook on the current game, on his rugby life after that semi-final in 2009 really, is scarcely positive:
It's a different era and guys are vainer now. They don't swat down loads of pints.
If Denis Leamy didn't get six pints after a match, someone's head was going to roll.
By virtue of the fact that he has survived professionally this far into his thirties, O'Callaghan is unquestionably aware of why treating your body in such a manner won't necessarily work.
Yet, looking back at that era, O'Callaghan realises that "the likes of Peter Clohessy, Mick Galwey [and] Dominic Crotty set a culture and values for the rest of us" at Munster to follow:
There wouldn't have been one medal [won] without any of the three of those guys and their selfless acts.
Although the lingering feeling for O'Callaghan seems to be touching on regret (even if he wouldn't go that far), his career remains one of the outstanding few in Irish sport.
See Also: Donncha O'Callaghan Reveals The Effect Anthony Foley's Loss Had On Munster