Paula Radcliffe insists the Athens Olympics represent the chance to complete some "unfinished business".
Britain's brightest Olympic hope goes for gold in the marathon, aiming to make up for the agony of missing out on an Olympic medal four years ago.
"As an athlete, I feel there is unfinished business," she told BBC Radio Five Live.
"I'm a stronger person now and have more confidence - and that is the big factor the marathon has brought me."
Radcliffe is also entered in the 10,000m, offering the chance to make up for an agonising fourth-place finish in that event four years ago.
But she insists the marathon represents her sole Olympic focus, though says she is still keen to taste glory on the track.
"Everybody thinks of me as a marathon runner but the track is still important to me," Radcliffe said.
She added: "As an athlete there is unfinished business on the track and it's important to go on and win medals and major championships.
"I always believed I could run a good marathon but just to be able to think at times that I am the best in the world is great.
"That, without being big-headed about it, gives me confidence and I hope to translate that to the track."
Radcliffe was swallowed up in the 10,000m Olympic final in Sydney
Radcliffe's preparations are now at their peak and her gruelling training schedule at her Font Romeu base sees her putting in 160 miles every week, including morning and afternoon runs.
But the determination born out of her disappointment in Sydney, where she led for 20 laps of the 10,000m final before being passed by Derartu Tulu, Gete Wami and Fernanda Ribeiro, has helped her relish the punishing training regime.
"It is tough and there are some days when I would like to go shopping or meet a friend for coffee, but I don't do that when I'm in a hard stage of preparation," Radcliffe said.
She added: "If I'm going to do something I'm going to do it properly and give it everything.
"There will be plenty of time to do other things when my career is finished - and I enjoy doing what I do."