You should read Malcom Gladwell's 'Outliers' - he provides a rich, detailed statistical analysis of why self-belief alone is not sufficient to achieve success - and as far I can see Lance Armstrong's self-belief wasn't enough either - not only did he need millions of dollars of investment in cycling infrastructure, that still wasn't sufficient for him to win, he needed stimulants as well, and he also needed to cajole his younger team members into doping too. All of this was necessary in an era when doping was pretty much the norm!