You don't need genius to finish a dissertation, just the ability to stick with a long project. About 2% of Americans have doctorates and about 2% run marathons, both achievements that come from commitment, not raw intelligence.
Many people believe you got to be a genius to write a dissertation. Yeah, you got to be smart. But you don't have to be a genius. You have to be able to take on a long term project and follow it to the end. I've heard once that 2% of the US population has a doctorate and also 2% of the US population has run a marathon. You know, it's not the same. There is overlap. People who can take on long term goals and complete them.
