The greatest lesson of grad school is that academic credentials mean absolutely nothing. Some of the dumbest people I've ever met are grad students who are half a step away from earning their PhD. You can be an absolute moron with no capacity for critical thought whatsoever and still make it to the top of the educational hierarchy. The only thing that determines academic success is your capacity and willingness to submit yourself to the disciplinary mechanisms and standards of the university system. If you follow all the rules (and shill out enough money) you can make it to the top fairly easily.