'I try to forget I'm the best in the world'
Many essential ingredients go into making a sportsman the best in the world - natural talent, the right genes, hard work and first-class coaching. Sometimes the decisive factor is the simplest of them all: raw determination.
"This is the time of year when you don't want to do some of the sessions, because you know you're going to be crawling along the floor at the end of them," says Dai Greene. "Then you think, I've got to get up and do another 300m, because I'm the world champion, and I've got to set the standard."
Greene is used to setting those standards high. He is reigning European and Commonwealth 400m hurdles champion, and has been British number one for the past three years. In winning gold at last summer's World Championships in Daegu he achieved something no other British male had ever done in his event.
For most people that would be cause to celebrate, to feel wonderful about the world and your place in it. Dai Greene is not most people.
"It didn't feel like the greatest thing," he says. "I wouldn't say it was a feeling of emptiness - when I did cross the line first I thought, yes, fantastic. But at the same time I didn't find myself getting carried away with it.
"I felt, 'well, I expected this to happen'. Then it was 'right, I've achieved that goal. That was out of reach before I set it; now I'll set another goal and try to achieve that.'"
Kriss Akabusi, the only man left ahead of Greene in the all-time British rankings, admitted to feeling depressed in the days after winning world bronze in 1991. With his great ambition achieved, his life suddenly felt stripped of its primary purpose.
"I can certainly sympathise with that emotion," says Greene. "The step up I'd wanted to take last year was from maybe top three to number one in the world. So I don't think becoming world champion felt like that massive a deal, even if the overall achievement over the years was a great one."
Being number one in the world brings its own unique problems. John McEnroe once described it as the loneliest place in sport. From being the hunter, always someone ahead of you to chase, you're suddenly out front, the target for everyone else.
"Before I achieved it, I wondered if I might struggle," admits Greene. "I was worried - I'd always wanted to the best in the world, and now I've done it, am I going to struggle for motivation? Am I going to become complacent?
"I was surprised when I started back training how much I still wanted it, how much I really wanted to push on.
"I try to forget I'm the best in the world. It is nice sometimes when people come up to you and say, 'Alright world champ?' or 'How's it going, number one?' Those sorts of things can give you a lift in training, but the best thing to do is try your best to forget it.
"Just because I won the world title last year doesn't mean I have a divine right to anything this year. My hunger for that Olympic gold medal is just as strong as anyone else's."
Greene is not the fastest 400m hurdler in the world. In 2011, six men ran quicker times than he did. He was only the fifth fastest man on the blocks before last summer's World Championship final. Despite that, it was Greene who triumphed when all others failed.
How? There is immense mental fortitude to go with the physical and technical strengths. As his coach Malcolm Arnold told me, "You see some athletes who, when it comes to racing, go down a level. The really good guys who succeed go up not one notch but two. That's the final piece in the jigsaw. And Dai can do that."
"There isn't a lot between the eight guys who lined up for that final, so a lot of it is in your head," agrees Greene. "Sometimes I'll be thinking, 'this is a fantastic race, I can't wait for this', but I'll look at someone else and think, he's gone - he's too nervous.
"I looked around in the call-room [in Daegu] and I could see other people weren't handling it as well as me. Which was great. It gives you a lot of confidence when you see your rivals can't deal with that situation, yet you can.
"There were athletes a lot older than me in that final, and with a lot more experience, but they were still suffering with nerves. That showed at the start, and it showed during the race.
"I knew when I stepped on that start line that there were probably three of us left going for that gold medal. And I didn't feel as if I was overly nervous or panicking at any point. I felt very much in control. I felt rock solid."
Greene is confident he can triumph in London on 6 August. Photo: Getty
Where does that ability to cope with such immense pressure come from? Has he always been this way?
"I've always been laid back. But as you get better at athletics you get better at coping with the big races. At the  European Junior final I felt nervous. European under-23s, nervous. When I was in the world final in 2009 I was struggling to hold it together through the rounds. I felt the whole thing getting to me.
"But I became more confident and more accomplished with every step I took, because I'd managed to take more control over the controllables - training, preparation, diet, sleeping habits, routine. That's where my confidence comes from. That's what keeps me calm.
"If I'd have shaved the odd rep here and there, or not done the extra core session, or not eaten properly, I would be more nervous. But I've done everything I can to prepare for any race."
Greene is currently at a UK Athletics camp in Stellenbosch, South Africa, soaking up high-volume training in temperatures that have climbed into the 40s. If that's taking warm-weather training to an extreme, and is rather different from "the top of a windy hill in Bath", as he calls his regular training base, it is here that the groundwork is being laid for the Olympic assault ahead.
When Greene and Arnold sat down to plan for London 2012, there was agreement on what was needed: more speed. For now, perversely, that means working on his endurance base - nine lots of 300m hard; 45 minutes of 60 seconds hard running, 60 seconds rest.
"When you arrive here and the sun's shining you find yourself wanting to run fast," he says, "but there are seven months until the Olympics, and you don't get medals for running fast in January."
As the weeks of hard graft go by, the days of extra core sessions and crawling along the floor, the Olympics will be a constant by his side.
"Until two weeks before the Games I'll be thinking, 'this is the biggest competition of my career, I've got to keep going and keep getting better'. Then I'll switch and start thinking 'they're just another race, just another race' because you don't want to put them on a pedestal and start getting hung up about it all."
Does he ever allow himself to daydream about winning gold on the night of 6 August?
"I do wonder sometimes, I do think forward. If I'm struggling in training I think, remember that feeling of crossing the line and beating everyone, whether it was the Commonwealths or Europeans or Worlds, and that I don't want to be losing those races.
"It makes me finish the rep or finish the session. I think, I've worked so hard to get to the top, I don't want anyone to knock me off.
"But I don't think about what I've achieved. I don't think about how what I've done has only been done before by a handful of people. I don't think any of that."