On a fleeting visit to Dublin, the larger-thanlife comedian laughs heartily when I mention the above, denying the three charges emphatically.

He's clearly amused that somebody somewhere has gone to the trouble of making up random pieces of information about him and he's even more impressed by the fact that they've taken on a life of their own.

"It's fantastic, " he says with emphasis. "I'm forever having people ask me about it in interviews and I'm quite happy to let it fester. In fact I hope to open it up to the nation on The Panel. I want to know who is responsible for writing this ridiculous trivia in the first placef" Although he doesn't collect Coca Cola bottles, he sips on a pint of Diet Coke, apologising for being a little hungover.

"I'm not at my most lucid, " he confides. While we're talking he also fiddles with an Aer Lingus baggage-handling receipt.

But he says he paid for it.

I suspect the main reason for the made-up trivia is the fact that although O Briain is all too happy to talk about his career;

he's extremely guarded about his private life. He claims it's because he doesn't agree with the culture of celebrity in which we live, but I suspect it's also to do with the fact that he's extremely shy.

He hides it well on stage; where he appears confident, brash and very witty. But in person it's harder to disguise, obvious not only in his reluctance to talk about his private life but also in his manner. Although he's surprisingly polite, he's also a little self-conscious and very wary. He's a clever man but you can imagine him getting impatient easily. He comes across as quite serious but clearly doesn't like to be thought of as such.

"I struggle with the cliche that all comedians are serious people, " he says. "There is a notion that we're all contradictions on and off stage which tumbles into the hoary idea that we must be depressed off stage, and it's wrong."

O Briain is definitely ambitious. At 34 he's one of the busiest comedians around, and somewhat of a workaholic. "I'm ridiculously busy and I will be for the next year, " he states matter-of-factly. "Of course, I have to make hay while the sun shines."

In the coming months, the Bray-born comedian has a UK tour of 60 dates to complete as well as a five-day stint in Vicar Street, Dublin. He'll perform at The Cat Laughs Festival in Kilkenny in the summer. Then there's another series of the BBC programme Three Men in a Boat to film and towards the end of the year he'll release a DVD and possibly do some more touring.

"Then I might take a short break, " he says, sighing at the thought his work load, but emphasising that he has no complaints about his job. "I adore what I do. The two hours I spend on stage during a show are playtime. Of course I have some nights when I think at the beginning, 'Oh Christ, I have to get up and do it all over again, but once I know what kind of audience I'm dealing with it's fine. You know, you can read an audience by its immediate reaction. It's very different to the response from an individual. I can tell how the gig is going to go from the moment I walk out and say, 'Hello'."

The gigs have been well received since O Briain first tried his hand at stand-up comedy as a student of mathematical physics in University College Dublin. "I was very shy back then, a bit of a nerd, " he says, a little embarrassed at the thought. "I used to go to debates and I thought it was very impressive, but I'd think to myself, 'Oh God, I could never do that.' All the time however I was storing up buckets of envy and rage and eventually I gave it a go. I remember coming up with my first joke as I walked around the campus at UCD.

It was a joke about the faculty of law and when I got up to tell it I got a good reaction from the audience and I started thinking, 'Wow, I can actually do this.'" The comedian soon became a well-known speaker at college, being trawled out to host blind date shows or fresher inauguration meetings. In fact, he liked college so much that he stayed on for an extra year and helped to set up the University Observer newspaper. By then he had abandoned the idea of working in mathematical physics and was aiming instead for a media career.

He seems an unlikely candidate for children's television, but after college he landed himself a job as presenter of Echo Island an RTE show for children. "Kids' TV is the gig that's available to you when you're 22, " he says. He learnt how to work in a studio as a result and it stood to him later on when he began to host TV shows.

In the meantime he had branched into journalism, writing a weekly column for the Sunday World.He was doing comedy gigs at the same time. "At the end of three years, stand-up emerged as what I really wanted to do, " he says.

"So I decided to give it a go full-time and I've haven't looked back."

These days he combines stand-up routines with presenting. He also part-owns Happy Endings production company and makes regular appearances as a guest speaker at events.

For the past four years, O Briain has been living in the UK, and he loves it. "I'm very, very comfortable there, " he says.

"It's kind of a world centre for comedy, which is great.

There's lots of scope for work and some of the people I work with are my heroes. For example, I recently worked with Stephen Fry and I had to pinch myself, 'Oh My God, I'm working with Stephen Fry.'" He owns a house in London and says he has no intention of returning to Ireland to live. But he does fly back on a regular basis. He also works abroad. "I've done gigs in every continent except South America, " he says. "I've worked in Dubai, Japan, Shanghai, Hong Kongf Usually the audience is made up of ex-pats; Americans, Australians, English and some Irish, most of them bankers 'doing' the Asian market for a couple of years. It's great because I get to see the cities I work in. What's more I view them in a very alert way because I find myself walking around before the show looking for that one-liner."

Beijing in particular appealed to him. "Beijing is different, " he smiles. "Nobody comes to Beijing to spend two years working, and by the time I got onto the stage I'd figured it out. I opened with the line, 'You guys aren't here because you work for Andersons or Deutsche Bank. None of you ever really intended to live in this city. You're all here because you're running from something.'" He sits back in the chair. "I got a tremendous cheer from the audience."

Of course, coming up with material for shows is the bane of every comedian's existence and O Briain is no stranger to writer's block. "I write in the run-up to a show. For example, if I'm doing the Edinburgh comedy festival in August, I take June and July off and I walk around looking for humour in the simplest of things. I go into a hyper-alert state where everything is a potential joke and I end up with reams and reams of paper full of jokes, but a lot of it is really, really lame. It's not easy. I go through an identity crisis each year and I'm always looking over my shoulder at last year's show thinking, 'That just happened and I'll never be able to do that againf' "When I've written the material, I've got to try it out on an audience, usually in a little room somewhere with a handful of people. I literally go in with sheets of paper and try the jokes. For example, 'The United Nations is run by a dwarf ', and the audience go, 'No', and I go, 'Right. Cross that one off.'" I wonder how he relaxes when he's not working. Does he have any hobbies? He looks awkward when the question is posed.

"That was always the sentence I hated on the CV. It's like the French oral exam at school. 'J'aime la cinema et la musique.' I like taking walks and staying in and catching up on TV shows which I record with my Sky Box; the greatest invention in the world."

And he's off talking about television gadgets with enthusiasm, but I interrupt and ask whether he likes a drink or two. "Oh yeah, of course, " he says. "But then I'm surrounded by bars and restaurants in my line of work. It's not a question of, 'Oh heavens, I can finally go out.' Curiously I work in bar with a venue every night. So I go out and meet people and talk shite or else I play with the cats."

He has two cats called Nero and Lockwood which he got from an animal welfare shelter, but like most men he's wary of calling himself a 'cat person'. "I'm okay with them, " he says, looking a little frightened. "They're an interesting feature around the house." But does he have a girlfriend, I venture, knowing that he is reported to be getting married this summer?

At this point his facial expression changes and he closes up so much it actually makes me wonder if he has some deep dark secret to hide. "I won't go into it, " he says emphatically.

"I've never found a reason to justify going into my personal life and I've a million reasons not to. It's easier on stage if people don't know anything about me because I can make it up. Frankly, if I have anything to say it's already in the show.

Besides it's a small step into the evil world of celebrity and I just can't stand to be thought of as a celeb."

But does he aspire to having a family eventually? "No, not in a way I'd wish to discuss in a newspaper, " he says half-covering his face with his hand and peering out from behind it.

"There's too much of that shit in the media already."

It's clearly time to change the subject and I ask how he deals with being recognised in public. "A guy on a plane came up to me one time. He roared at me, 'You're much uglier than you look on TV.' He walked off the plane before me and in the airport I passed him on my way to the toilet. He was coming out of the disabled loo. He pointed at it, 'You can use that because you're stand-up is so handicapped.'" O Briain pauses. "The worrying thing is that maybe he thought it was banter and that I actually liked it because it was refreshing." He screws up his face and adds that he no longer listens to criticism. "You have to inure yourself to criticism. It's going to happen but you can't be sensitive about it."

And what's next for Dara O Briain, the non-celeb? "Frankly my career has been such a random thing that just happened to fall into place in the last few years, " he muses. "I've never had a masterplan to get me this far and I don't have one for the future."