Inri is talking about the conscientious personality trait . This is highly correlated to success in school and in the workplace.
You may consider yourself a struggling student but often a struggle is needed for success. If you're doing this already then have faith that you are on the right path as eventually it will be borne out. My point is that you can learn a conscientious personality, and you can become smarter and stronger willed. Every human is born with some willpower. Every human is born with some intellectual ability. Intellectual effort and willpower are both cumulative. They are like muscles, simple exercise of them grows them.
I have never met a man or woman who has fulfilled their potential.