"I'd obviously let them down. It was definitely one of the worst times of my life"
"I literally sat there for two hours weeping. It was one of my biggest regrets."
France in the final pool game. It was time for Ireland to make a statement at the 2015 World Cup.
The French had been yapping all week, talking the talk and giving Ireland lots of it. Hearing all of this, and with the big game approaching, Sean O'Brien was wired to the moon.
He'd end that day as man-of-the-match, in a 24-9 win for Ireland but that didn't tell the full story of a day the Carlow man still labels as one of his biggest regrets in rugby.
Speaking at Baz and Andrew's House of Rugby live in Limerick on Thursday night, the Tullow tank took us through the rollercoaster that was the France game, and the fall-out that followed his clash with Pascal Pape.
"Before we went out for that game, I'd given a bit of a spiel in the dressing room. I was fired up all week, because the Frenchies had come out and said, 'We're going to bully these lads. We're going to physically dominate them. We're going to do all these stuff to them'.
"And I was kind of saying, 'You're going to do absolutely none of that! We're going to do that to ye!', in my head. So I kind of got revved up in the changing room and then we were in the tunnel on the way out and I turned around - I think I was fourth or fifth out - and I said, 'Nothing stupid early on, lads'... and then, 90 seconds later, I'd a fella punched in the stomach, myself! And I'm missing the quarter final against Argentina. And I remember, it was definitely one of the worst times of my life, that citing, and going into the Argentina game," says O'Brien.
"I remember my two nephews, all my family and my sister were in the room and I broke down on the way to the table. I literally sat there for two hours weeping, I just couldn't contain myself. I'd obviously let them down..."
The case went to a hearing then, and what really frustrated O'Brien was Pascal Pape's performance there.
"Sitting in the hearing listening an international player, telling lies. It baffled me like. He said to them he was in hospital for a night and that his rib was broke. Then the doctor's report came back and none of this had happened..."
With O'Brien, O'Connell, Furlong and Sexton amongst others all ruled out of the Argentina game, a depleted Ireland side bowed out at the quarter final stages yet again.
That heartbreak had O'Brien determined to make amends this time around, and that's what makes his hip injury all the more frustrating.
"We were missing Paulie, Johnny and a few lads - one of us on the field and I think we would have beaten the Argies. It was one of my biggest regrets...Terrible time and that's why I really was pushing hard to get to this one. I wanted to make up for what I had done in the last one..."
You can listen to the House of Rugby live from Limerick here.