Tiernan joked, "I kind of stopped gigging in England for that very reason. I wouldn't say English people are no craic. There are some fantastically brilliant English people. My stupid theory on it would be they don't see the wisdom in undermining what they see around them as much as we do. Poor English people do."
They went on to discuss how rugby has become much more physical in recent years and O'Callaghan agreed, noting that he has particularly noticed it in the last three years.
Speaking about what he does for a living, O'Callaghan laughed, "Tommy, my job is to put my head between two asses and push, you know what I mean? There are better job specs out there!"
At this point he squashed his face together with his hands, prompting Tommy to quip, "When you said that I'd a vision of you being born!"
Tiernan commented on the bond that rugby players have throughout their lives and for the former Munster star he said it boils down to the losses rather than the wins the guys share together.
"I'm massively thankful for rugby - you've had successes, won things for Munster and Ireland, but I'm not just saying it, it's the relationship you build, it binds you together. I'm not chatting about the victories, I think it's more so the losses.
Donncha O'Callaghan on The Tommy Tiernan Show. RTE
"When you're in a trough only the guy in the dressing room knows it. Your family and your friends, they can speak like they know what you're going through [but] they haven't a clue."
Tiernan commented that there is an "innocence and a charm" about O'Callaghan and wondered where the attacker on the pitch comes from.
"When I watch games back sometimes I'm looking at it going, 'Who's he? I don't nearly know that person going across' because off the pitch I like a bit of craic, a bit of fun."
Of his match persona, he joked, "If I went around like that the whole time there'd be people crossing the road to get away from me. It's not a good way to live your life!"
Speaking about coming to the end of his career, in May this year, he pointed out the difference between his younger peers in his Worcester Warriors Whatsapp group and the Munster lads' (who are "all hitting 40ths and 50ths) Whatsapp.
Donncha O'Callaghan was an excellent guest on The Tommy Tiernan Show, very funny and honest.