INTERVIEW:David O'Doherty has a lot to talk about. There is the book about sharks, the sell-out Fringe show, the musician girlfriend – but he's no good at interviews. SINEAD GLEESONtries to coax him out of his shell

I’M UNDER NO illusion that what I do is niche. When I was in Edinburgh, I had two quotes on my poster that were from the same newspaper, printed in the same week. One called me ‘a national treasure’ and the other one said ‘not everyone’s cup of tea’ – and I’m okay with that.” David O’Doherty is looking dapper as we sit outside a Dublin café midweek. The weather looks ominous and he offers some “spare clothing” (he’s wearing various layers) in case I don’t have a coat. He also announces that he’s “not very good at this stuff” with a nod at my recorder. On the day we meet, it’s a week until his new show opens at the Dublin Fringe Festival, which has been sold out for weeks. Not bad for a guy who once worked as a chauffeur to singer Diana Krall and was “really bad at it”.

Rory Sheridan's Tales of the Antarcticaconcerns a reluctant explorer, which is less a homage to Aidan Dooley's Tom Crean show, and more about blurring the lines between fiction and reality. O'Doherty's stand-up routines have always been predicated on is-it-real-or-not story-telling, but this show is about extending that idea, and pushing himself.

“I first saw the Crean show in Edinburgh and it was a huge inspiration. Having worked in the realm of made-up facts in my stand-up and books, it seemed obvious to do a show about a made-up person. What I didn’t realise is that acting is hard, especially for an hour [laughs] and how long it actually takes to learn a 30-page script. But I performed it 27 times at Edinburgh and learned a lot. It’s trial and error, but it’s definitely the most satisfying thing I’ve done.”

Edinburgh is where it all really began for the Dublin comedian. After winning the So You Think You're Funnycompetition at the city's Fringe Festival in 1999, he followed it up in 2000 by scooping the Perrier Newcomer Award (he won the overall festival prize in 2008). It was where he made his name and somewhere he returns every year with a new show. "The only point in going to Edinburgh is to challenge yourself. I've gone every year since 1999, and it's so inspirational. It reminds you of why you do it."

He cites the absolute conviction required to be a stand-up, because of those early toe-curling gigs. “At my first solo show at Edinburgh there were five people in the audience, who all won tickets on the radio. After a few minutes, they all got up and left, so I burst into tears and went for a pint with the tech guy. No one has the thick skin for it at first, but you develop it.”

O’Doherty’s style is idiosyncratic, mixing scripted humour, off-the-cuff chat, and songs. Spontaneity is crucial and it helps stave off the kind of nightly repetition that would cause him to “lose my mind . . . It works because if you establish yourself as a real person, people aren’t scared to talk to you. So, sometimes at my gigs, I say something that’s factually incorrect and someone in the audience corrects me. I ask them to explain what they’ve said and some of the best stuff comes from those chats.”

While O’Doherty tends to tour alone, the loneliness is outweighed by the opportunity to write material. As an observational comic, he picks up material, magpie-like, from experiences on trains and while travelling. Deadlines also help. “Cole Porter was once asked ‘Which comes first - the music or lyrics?’ And he said ‘The phonecall,’ and it’s like that for me. There’s nothing like having a gig tonight to force you to finish something. I write a lot on tour, try it out and and record the gigs. Often ideas happen on stage, but your brain is working six times faster, so you don’t remember everything. Listening back gives you ideas.”

Ask most people about O’Doherty’s MO and they’ll mention the songs. Delivered in deadpan, over a keyboard riff, they tackle everything from misdirected text messages to iPhone owners. Is the keyboard a prop, or is he a frustrated musician?

“Oh, I wanted to be a piano player, but I wasn’t very good. My dad is a pianist, and he has natural ears for it. He comes to my shows, but then he’s a jazz musician, which is possibly the only less legit job in the world after comedian. No, he’s very supportive, and never put pressure on me to get out in the world when I was living at home and writing.”

Despite annual trips to Edinburgh and regular work in the UK (including a stint presenting BBC's music quiz Never Mind the Buzzcocks), O'Doherty has never felt the urge to follow in the footsteps of his contemporaries Dara O Briain and Ed Byrne, who live and work in the UK. "I've spent 30-something years assembling a coterie of friends around me who I really like hanging out with, and who I find inspirational. I like being at home, visiting my family – I've never needed to move."

O'Doherty's partner, the singer Lisa Hannigan, is also based here. This week, as the comedian's Fringe show kicked off, her hugely anticipated second album was released. "It's insane, she's doing seven interviews a day." He veers the conversation towards friends he admires, including novelist Paul Murray, but admits that Hannigan "helped think up some puns" for his new book, 100 Facts about Sharks. Like its panda predecessor, it's a funny miscellany of random information that may not be true. The book's publication in early October marks the beginning of a busy period for the comedian, including an Irish tour (he plays Dublin's Vicar Street on October 1st) and a children's book. The book will be about "robbing the travelling bank in Achill" (he used to visit the island as a child to see his grandmother). On the long journeys, his father played tapes of old comedy shows such as The Goon Showor Round the Horne, as well as Lenny Bruce and later Kevin McAleer and RTÉ's Scrap Saturday. "I went from being this massive comedy fan on tape to going to every single gig I could for five years . . . but I want to keep doing different things, so I'm not under pressure to do bad television or awful clubs. My main career goal is that I will never have to go back to temping, but maybe I should, because it would remind me of how lucky I am, especially when you're sitting in your jocks trying to think up jokes."

David O’Doherty Is Looking Up starts in Vicar Street, Dublin on October 1st. 100 Facts About Sharks is published by Square Peg (€11.30)