The competition, which begins Saturday, will see the 33-year-old Texan try to beat the record he set last year.
His mother's opinion was also shared by Armstrong's coach. Both said the key to his success is not so much his amazing skills and ability to generate tremendous speed, but a burning competitive drive that leaves no detail unexamined in the pursuit of a goal, USA Today reported Friday.
"I am focused," says Armstrong, who plans to retire after the current competition. "I've always been that way, even as a kid. That's because I have a responsibility to perform at my best. ... I'm paid to be obsessed. I'm paid to win."
Some tour experts wonder whether Armstrong will be able to cinch yet another win, noting he has raced little this year. When he has, his recent performances have proved largely disappointing. But others believe he is fit enough to win again.
The three-week, 2,255-mile tour stretches from the Atlantic coast through Germany, down the Alps and Mediterranean cost and Pyrenees mountains before ending up on the Champs Elysees in Paris.
The course undercuts Armstrong's strengths by offering shorter individual time-trial stages and just three mountaintop stage finishes, USA Today said.