That said, I've done pretty well on aptitude and interpersonal skills despite being a pretty poor student with low self-control. It's all a matter of finding work that values fast thinking, improvisation, and flexibility than slow and steady performance and, to be honest, decent interpersonal skills probably trumps both aptitude and self-control in the business world.
It's VERY hard to be a Gauss, but it is possible [after all, he did exist]. The adage about the relationship between inspiration and perspiration applies to the broad middle part of IQ bell curve. It most emphatically fails at either far shoulder. Therefore for most people persistence trumps a relatively weak ability. In the case of conspicuous disability [retardation] persistence does not pay, or pays very little. In the case of conspicuous ability [genius] persistence plays much less certain role, for such people could, and sometimes do, think in qualitatively different ways, by leaps and bounds. Sometimes they need not be persistent.