Brian O'Driscoll is terrified. Not of physical pain or even losing. He's petrified of what is to come: the unknown, life after rugby, an existence beyond the one that has made him the ultimate centre of attention. "When you've done something for more than a third of your life," he says, "your whole adult life, and then all of a sudden you're going to have to switch off and say, no more, you want to grasp as much of it and enjoy the last few years of it as much as you can. Because you can't get those years back."

At 32, O'Driscoll's smile is style-revealingly boyish. The dimples wrinkle either side of his mouth and some times it is as if he is telling you one thing and thinking another. But not today. The press conference mien is dropped for a while and he wants to share some of his feelings, fearful ones as well as upbeat. He is loving his rugby, mainly because he knows he might have two, maybe three years left.

He does not like to think of himself as institutionalised but he suspects that is exactly what he is, a product of a game that once was played for fun but now for money, and quite a lot of it. So, locked in to his celebrity and his financial commitments, he is concerned about what will happen to him when his body can take no more hits and his enthusiasm for what he recognises as an essentially childish pursuit diminishes towards pointlessness. It is the refrain of all athletes. Except O'Driscoll is an exceptional one.

There is another difference: "BOD" is, without argument, an Irish superstar, a description that makes him cringe but cannot be avoided. It is surely incomprehensible that he would ever struggle after rugby. He does not see it that way. He is, he reckons, the same as all the rest. "Having seen guys in the past who have stopped playing and gone, 'Right, what'll I do now?' That prospect frightens me greatly. They lived in different times, Celtic tiger times, where the world was your oyster. Now it's dramatically changed. You don't want to go from what you're on now to zero, and all of a sudden it's, right, how do I pay my mortgage or how do I live day to day?

"Your name or what you've done on the rugby pitch is not going to carry you through for the rest of your life. I realise I'm going to have to eventually do something else and that does frighten me a little bit."

It is not all despondency. "I still get a great buzz from rugby," he says, rueful but realistic about Ireland's World Cup campaign, which ended perhaps a match short. The past three years, I've had a lot of fun, going in to training every day. It's a good laugh. At times over the years it might have felt like a job, a bit of a chore. It doesn't feel like that now."

If he has reached a comfort zone of sorts, he is aware too that there have been moments when he railed against the disciplines of his calling. "You've limited room for rebellion, but there was a bit with the blond hair [in 2002]. I was in control of that. I look back, and I go, it was a bit immature, yeah, but no one could tell me what to do on that."

It sounds inconsequential, but that daft gesture perfectly describes life inside the goldfish bowl. "They had so much control of other things," he says, that smile breaking through again, "what you're to eat, and you're not to socialise here, and be careful doing that. It was an outlet for me, to stick two fingers up and go, this is mine; as bad a decision as this might be, I'm gonna roll with it, and nothing can be done about it."

In New Zealand, England's players, most of whom he knows well, went a step or two beyond dying their hair. O'Driscoll has some sympathy, but not a lot. "There were a few guys a bit out of line a couple of times but they did get absolutely pasted [in the media]. And then you read what Lewis [Moody] has been talking about as well [admitting some team-mates let themselves down in the bar] and you go, well, he's the captain of the team, maybe it was as bad as was made out. Were they looking to get after them? It's a hard one to call."

But what of his old friend, Martin Johnson, whose job it was as coach to look after this perceived rabble? As he said, if you can't have a few beers, what's the world coming to? "I totally agree with that," says O'Driscoll, "totally agree. I think it is a shame that anonymity has gone out the window because, at any stage, anyone who spots someone [having a drink] can tell the world about it in the time it takes to text it and send it off."

As for himself, the attention in a place the size of Ireland is magnified to an extraordinary degree. Does it ever make him feel uneasy? He picks his words like he would a gap in the England back-line. "Sure enough when I walk away and in an hour's time I'll think of a situation when I'm very uncomfortable," he says slowly, pausing. "I was uncomfortable ... yesterday in the airport when somebody asked for a picture, then it kicks off a load of other pictures and then [you're] the centre of attention outside boarding gate 409 [the point of departure at Dublin airport for Aer Lingus flights to London, a journey he takes as if catching a bus]. I don't think I'll ever get used to something like that. I don't really want to be the centre of attention."

To which a nation will rise up and cry, "It's a bit late now, pal." As he sees it: "Our five million people, it feels like five thousand people some times. But that's great, too. There's the flip side to it: people are still being nice and asking for photos, so something's going all right. You have to treat every person that comes up to you as best as you possibly can, provided that it's in a polite circumstance. If someone's rude to you, I don't think you have to be super nice back to them. You can do the job and send them on their way."

O'Driscoll has had a reasonable run with the Irish media, although he had a nightclub phase when crustier elements came down hard on that briefly blond head. "There are certain individuals I have a big respect for because I truly believe they know what they're talking about. It's not just column filling. And it's hard, I'm sure, for a journalist to constantly churn out good articles, but there are certain guys that you know their line of questioning when they come to you. They've done their research. There's a guy that works for a radio station here [Simon Hicks] and I look forward to his questions because I know that they'll be challenging.

"I don't mind getting criticism provided it's warranted or it's projected in the best way. But people who attack personalities ... and there's a bit of that in Ireland, a bit of the shock-jock thing going on. That's fine for people's entertainment but, from a players' point of view, it doesn't hold any value."

Outside in the wet streets of Dublin, For Sale signs flutter in the autumn wind like flags of resignation on the many glittering office blocks and fine apartments lining the Liffey. Ireland is in a state of perpetual nervousness, and their most celebrated son feels the chill too. Does he sometimes not wish he were playing in amateur times, when the media and society did not demand the price he and his fellow professionals have to pay?

We mention the riotous 1974 Lions, who drank and caroused their way through South Africa and returned unbeaten – and still lionised. "Well, life has changed from '74. We're playing in a professional era where people expect more than you just go out and kick lumps out of each other and then go and get slaughtered together. We've moved on from that: it's kick lumps out of each other and then you go home and have an ice bath."

Whatever his ability to generate excitement with a flick of the hips and that hair-blown dash to the try-line that can light up any gloomy day, O'Driscoll is as pragmatic as any working man. The son of Dublin doctors who grew up in the suburbs "well-behaved enough", he is, says someone who knows him well, keen to please his parents. "They were strict but fair," he says.

And O'Driscoll likes discipline in his rugby too, a little conformity. We mention Quade Cooper, Australia's errant Kiwi, who did not have a great World Cup. "He's exciting to watch ... but he's just a little on the loose side for me. It's about guys who don't make that many mistakes. And, if even they do, they're not that drastic mistakes."

It is the voice of caution. O'Driscoll knows his worth but is not a great risk-taker, on the pitch or in life. So, one more dash of speculation: in the days after Ireland has elected a new president, does the most popular man on the island every imagine he would reach for that high office? "No! No, I can't see it, for all sorts of reasons. It's a staunch no."

As we leave, his dimples crease deeply yet again and his eyes are laughing. At what, we cannot be entirely sure.

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