"I'm a very organised person. Methodical I suppose you'd say.That's why I just can't understand why I can't find my passport. I mean you'd think it'd be where I left it last time." he says, before diving into a drawer and coming up with the elusive document. "Right, exactly where I didn't leave it last time."
With that the passport is lodged in a pouch of his kit-bag on the basis he explains, "that I'm hardly likely to go away without that."
It's been a busy week for O'Callaghan with the the two final pool matches and it will lead directly into national squad preparation.
" Yeh, it's been a bit hectic right enough. We had a good run this week. Training was fairly light but just as intense as usual. The match against Ospreys was a real bruiser.They're a tough side, a good side.
"They made us work our socks off. I'd be very happy withour defence. It had to be good because they really came at us in the second half. The 'appy chappie' (Graham Steadman) is doing a great job on us even though, with that Lancashire accent or is it Yorkshire?, I haven't a notion what he's saying half the time.
"The game this week will be just as tough. We'll pay no attention to the result of theirs last weekend. Like, they rested a dose of their players, keeping them for us, don't ye know. So we're expecting more of the same this weekend as last against Ospreys. If it's anything like last time we played them, (Harlequins) in Thomond, it's going to be hard earned.