A PhD is more about elbow-grease than intellect. You do need some intellectual chops (in your field - you can be very naive outside it), but you need perseveran

A PhD is more about elbow-grease than intellect. You do need some intellectual chops (in your field - you can be very naive outside it), but you need perseverance more than anything. I've met some PhDs who would run rings around anyone in their niche, but would be (metaphorically) unable to tie their shoelaces by themselves.