And the reason he might be feeling 'very rested' is because in the month of November he played just two games of rugby, one for Munster against Ulster and the other for Ireland against the US Eagles.
So to say that he can't wait for the game on Friday against Castres is putting it mildly. "Ah yeh, really looking forward to it. Of course it's great to be involved with Ireland but none of us likes being left on the bench. I have to accept the situation, Paulie and Mal are playing well, I know that but this being patient thing is hard enough to do y'know.
We gave them a bit of slagging when yer man said they mightn't get on the Springboks side. So there was me thinking, yeh they mightn't get on the Sprinboks team but the way they're playing I'm not getting on the Irish side.
Then they go and destroy the Boks and it's 'Oh my God, what chance have I now.' But that's what it's all about I'm told. Being patient. Keeping the head down. Being patient. Checking for woodworm in me bum from that bench.
So you wonder if I'm looking forward to the game on Friday. ? You can sing it I am." And ahead of himself and his Munster colleagues the prospect of some carry over, not just from previous encounters but more recently, the game last Saturday.
"Well the lads were saying there was a lot of funny stuff going on alright. Well it wasn't funny at all if you saw the state of some of them after the game. And they're not the sorts to whinge over nothing like. But as far as we're concerned what's past is past. We'll carry nothing into this game. We'll handle it as we would any match and handle whatever is thrown at us in our own way.
We're going out to play rugby, not interested in anything else. Having said that though we're not ones for stepping back. " Having spent the last month rooming with Ronan O'Gara, O'Callaghan shares his space this week Marcus Horan in the Sofitel Hotel but refuses to be drawn on which one he prefers opting instead for a strait laced, "All I'll say is that they are both lovely fellas, model professionals.
I love them both to bits I really really do. I get on better with them than with most of my family. And I miss them when I'm not with them. I mean I miss them a lot, I really do. That's Marcus and Rog like, not my family."
And with that O'Callaghan heads off with an iron in one hand and an ironing board in the other.
"Going to do a bit of ironing Donners ? " Press Officer Pat Geraghty asks.
"No, I'm going surfing." replies O'Callaghan