Feynman told a story about his "one extra trick". He ascribed a certain amount of his mathematical prowess to simply knowing an uncommon integration trick that most of his colleagues did not. So when they failed to solve an integral, they would bring it to him, and some of the time, using his one extra trick, he would solve it, dazzling everyone.
Which is not to say that his one extra trick was particularly powerful, or widely applicable, but it was unusual, and it produced a difference in ability. Maybe Feynman couldn't solve more integrals than his colleagues, but he could integrate different ones, which made him useful and "smart".
Which in turn brings up the nature/nurture question of genius: to what extent is genius a matter of "innate" skill (in this case, that arises either from the circumstances of your birth or life) and how much of it is a quirk of your education, the one extra trick you learned (or didn't) that make you approach problems in a way different than your peers?