'The Irish are endlessly fascinated by themselves," said Terry Eagleton. I first read this quote in The Irish Paradox by Seán Moncrieff, a book about the Irish psyche and the political, cultural and religious contradictions therein.

Obviously, as an Irish man, I found it fascinating.

Moncrieff is fascinating. As a radio presenter it’s his job to be. He walks in carrying a suit over his shoulder, quip-ready and smiley even though he’s feeling “a little hassled”. He has this interview to do, he has to pick up his 24-year-old son from the airport (he has four children), he has a charity event to attend (hence the suit) and a radio programme to host. That last bit he doesn’t even mention. “I’ve been doing it such a long time it’s kind of second nature,” he says. “It’s kind of Pavlov’s dog. In a sense you go into [he clicks his finger and suddenly looks radio-presentable] radio mode.”

This is Moncrieff’s sixth book. The idea came from his publishers, but he had been thinking a lot about Irishness anyway. So he wrote about his own life, the political system, uniquely Irish forms of racism, our alcoholic extroversion, the urban-rural divide and many other of our national neuroses and contradictions.

He spent his childhood in the UK. “My mother felt living in England was a kind of affront,” he says. “She always instilled in us the sense we were Irish and pointed out if somebody was Irish. She had a grading system. If the people next door were Dubs, they were kind of Irish, but not good Irish. If somebody had a Mayo name, that was a good thing . . . She was born in 1917, so she had a British birth cert, but when we were in England she was a sort of crypto Provo.”

He recalls a Christmas panto where someone said, “ ‘Put up your hand if you’re from London’, and I put up my hand, and my mother nearly cut my head off. ‘You’re Irish!’ ”

When they moved to Ireland he had “a cor blimey accent”, he says, but adapted quickly. “[At school] some guy called me a ‘Brit bastard’. That really struck me: ‘Shit, I sound different. I think differently. There’s loads of little codes I don’t get.’ The accent was gone in three months. I purposely lost it.”

He laughs. He doesn’t want to overplay it. “It’s not like ‘my fucking pain as an outsider’ type shite,” he says, then adds: “But there was probably a little bit of that.” He offers to cry for the photograph.

Irishness seen as cool

Moncrieff started working in media “maybe out of a sense of already feeling different”. He went to work in London at a time when Irishness was seen as cool. “I had friends who were gay or who just didn’t fit in Ireland at the time, but they loved being Irish in Britain. It was Irishness stripped of the bigotry and confusing aspects.”

When he had his first child, he felt a "homing signal", he says. He entered RTÉ for the first time, working on Over to You with Nick Coffey. "[Coffey] referred to me as his batman and would bring me around the place. He'd bring me around RTÉ introducing me to people, and I had no idea what he was doing . . . He was trying to get me work, but I was just walking around like a flute after him."

Later Moncrieff presented The End, a cult success, and then the chat show Good Grief Moncrieff, a high-profile flop.

“That’s very cruel of you to point out,” says Moncrieff. He discusses its failure in the book. The critical mauling it received led to a senior RTÉ figure accusing him of endangering the licence fee. “I became slightly unclean. I had to go on the dole for a while, which was a surreal experience for me and the fellow in the dole office. He thought it was a joke at first.”

Irish people, he says, have a weird relationship with failure. “They don’t deal with it that well. If you’ve failed, you’ve always failed and will be a failure for the rest of your life. Since then my career has been over several times.”

Did he like working at RTÉ? “Eh,” he says, and pauses. “I had mixed fortunes . . . They taught me an awful lot and I would be eternally grateful for it. But I do remember days feeling angry going in and even more angry going out. It’s so big and relatively isolated from the rest of the world there’s a kind of village mentality . . . The amount of people I worked with who spent a percentage or all of their day speculating about what he’s up to, what she’s up to and what’s going on over there.”

Head of paperclips

He found the hierarchies baffling. “I remember going for meetings not being quite sure what the meeting was for or what they were trying to say. You’d find out the head of paperclips had a strong opinion on your programme . . . but not why that was important.”

He had a successful stint on panel show Don't Feed the Gondolas, but by the end he felt boxed in. When editing the programme "[I'd] look at myself and think, Well, he's annoying".

Then Newstalk came along. “[The station] wasn’t going that well. When they got their first set of results someone asked the guy who did the number-crunching, ‘What does zero mean?’ He said ‘What do you fucking think zero means?’ I went in and said, ‘This is the show I would like to do’. They might have said, ‘No, that’s nuts’. But they were kind of desperate.”

He devised an intelligent, wide-ranging magazine show held together only by his wit and his "woolly liberalism" and his own interests. It's outward-looking but always relevant to Irish people, he says. "An American academic might be on talking about racism in Alabama. but there'll be a parallel there Irish people can learn from."

The big issue exercising people right now, he says, is the refugee crisis. Racist responses frustrate him. Texts that begin “I’ve an eight-year-old daughter”, he sighs, always conclude with “therefore we should let people drown in the Mediterranean”.

He sometimes gets wound up on air, but regrets it. “If I try to engage in what they say and give a reasoned answer, it might be more useful than just taking the piss.”

What’s it like having a public persona? “I meet people all the time, and they expect me to tell 10 amazing stories. [They say], ‘God, you’re a bit quiet’.” He laughs. “People think that they know you and I suppose they do know aspects of you. But they don’t know the real me,” he says with mock outrage. “They don’t know my pain.”

Conspiracy theorists

He mentions that they keep a record of any threats or odd emails they receive. How often do they get these? “A few a week,” he says. “There’s a guy at the moment who thinks that if I ring up NBC or Fox, it will prompt a collapse in banking all over the world.” This man has called to Newstalk with a collage and sent in a strange video. “It was quite creepy really.”

He has seen, he says, an increase in correspondence from conspiracy theorists, but thinks “that’s a function of the net and globalised culture”.

He’s interested in how the internet affects us. He marvels at how we “genuflect at the Web Summit” and how people like to rant online “to show they care”. He calls this “performance piety”. He’s also fascinated with how Irish people repeatedly vote for self-interest, “yet go down the pub and give out about everyone else being self-interested”.

He is writing a novel, his fourth. He writes on the Dart, in longhand, “with a quill”. He doesn’t really make career plans, he says, “because my career has been over before”. But he would like his books to be more successful and he still enjoys his radio show.

Sections of The Irish Paradox are autobiographical. Would he ever write a memoir? "Ah, a lot of memoirs are tedious unless there are some very dramatic things that have happened," he says. "My life isn't very exciting. This is all I've got. I've shot my bolt."

• The Irish Paradox: How and Why We are Such a Contradictory People is published by Gill and Macmillan