Well according to a new book by sociologist, Malcolm Gladwell, yes it does.
According to him, the best way to achieve international stardom is to spend 10,000 hours honing your skills. The greatest athletes, entrepreneurs, musicians and scientists emerge only after spending at least three hours a day for a decade mastering their chosen field. But, there are also other elements involved: work ethic, luck, a strong support base and even being born in the right year play a role.
Maybe if we work out how much effort we put into learning a language, we can gauge just how much success we can hope for.