Jenson Button has admitted that retirement remains on his mind, despite having at least another two years to run on his current McLaren contract.

The 2009 world champion has no plans to quit just yet, and remains linked with various drives in the top flight despite his long-term commitment to Woking, but concedes that thoughts of life after racing still cross his mind as he considers his achievements. Despite beating team-mate Lewis Hamilton to come second overall in the standings, Button admitted last year that retirement was a real possibility after he landed his title with Brawn, but joining McLaren had given him such a new lease of life - and hunger for more success - that he can no longer put a timetable on his plans to stop racing.

"When I won the world championship and my [McLaren] contract was done, I definitely felt that I could also finish my career," he conceded at the time, having inked his extension at the Japanese Grand Prix, "But now, two years further down the line, I don't feel that this contract will be my last one. I've seen so many drivers finishing their careers earlier than they should have and regretting it dearly, so we have all that experience to look at. The fact is that I am doing something I love and something that I am good at and not a lot of people get that opportunity."

That sentiment was one that he echoed in a recent interview with Britain's Mail newspaper, where he conceded that winning his title had also been a moment of realisation that life would never be the same again.

"There was a big party for the team after I'd secured the championship," he recalled, "But I stayed for one drink and went back to my hotel. I sat there on my own for hours. It should have been the happiest night of my life but it felt like a total anti-climax. I sat and thought about what was going to happen next. I knew that, from that point, coming second would never be good enough. Once you become a champion, people expect you to keep coming first. You need to be a superstar every day of every week of the season. You're not allowed an off-day. You're not allowed an unlucky streak. It's a lot of pressure to live under."

The report estimates that Button's F1 success has brought him a ?53m fortune - a figure boosted from ?40m by signing for McLaren - as well as a model girlfriend, Jessica Michibata, and houses across the world, including one in Monaco, where he lives side-by-side with many of his rivals. However, despite appearing to have everything he could desire to live comfortably outside of the F1 bubble, as well as enjoying the distraction of competing in triathlons, Button - who last year claimed that he would want to continue racing even when his grand prix days were done - insists that he needs to know that he would not yearn for the thrill of driving on the limit.

"I never listened in class because I was always daydreaming about racing. I never thought for a moment about doing anything else," he revealed, "There was no guarantee that I'd make a career in it but I never had any 'plan B'.

"To understand the intensity of driving an F1 car, you have to be in it. When you're driving a 750hp machine at 200mph, the noise and the vibrations are incredible. The G-force when you take big corners is like someone trying to rip your head off. You hit the brakes, and it feels as if the skin is being pulled off your body. I sweat so much during a race I lose three litres of fluid. The adrenaline is such that my heart is beating 150 to the minute. The experience is like nothing else on earth. When I do retire, I know for a fact that I'll never be able to replace the incredible feeling I get when I'm driving an F1 car."

Having suffered his share of accidents, Button admits that fears for his own safety have escalated, but insists that they are not affecting the way he approaches the sport.

"I've had a few crashes in my career [and], once you've experienced something like that, you never lose the fear that it might happen again," he conceded, "To drive an F1 car you have to be a little mad. On the morning of a race, there's a mix of excitement and fear.

"If it's a wet track, then it's worse as you're not in control most of the time, which is the thing all drivers fear the most. You go down a straight and there's a wall of spray in front of you. If a car has crashed in front of you, you're going to hit it at 200mph.You'd have to be stupid to think that everything is always going to be all right. If anything, the fear intensifies as you get older but it's a hard thing to give up.

"[Retirement] is on my mind [but], in any sport, the trick is to retire at the right time. So many drivers say they look forward to retiring from F1 and they can't wait to live a more leisurely life - but, after four months away from it, they go stir crazy because they miss the constant buzz. I've still got ambitions within F1 - another championship would be a fantastic achievement."