The Tullow Tank admits he's not thinking of the end just yet.
In July 2014, Sean O'Brien admitted his body would be "in bits" whenever he retires.
He must have felt that fateful day looming large, just over months later, when he headed to the UK for his second shoulder surgery in the space of a year.
Rugby players have often been known to make deals with themselves - just one more season, just one more trophy, just one more game - but O'Brien says that, even in his darker moments, he never set any dates.
'I haven't made any deals like that.
'I feel like I'm in better nick now than I have been over the past few year.
'Some people say that the older you get, the more strength and fitness you lose. It's going the other way for me. Long may it continue.'
O'Brien is hopeful that Ireland have learned from 'mistakes of the past', when it comes to the World Cup, and insists competition for squad places remains high.
'There's a lot of [back row] lads in form; lots of competition... I never count my chickens before they are hatched.
The flanker, who captained Ireland to their 22-20 win over Scotland, has heaped further praise on the man that has Ireland humming - Joe Schmidt.
He says, 'As a coach, Joe gives you a lot of confidence in the game-plan. His analysis of the opposition and the way he man-manages people is brilliant.
'He gives you that opportunity to go out and play to your potential... It is great having that knowledge that, if you do what he tells ya, you're never too far away.'
