Nurture your mind with great thoughts, for you will never go any higher than you think.
Benjamin DisraeliHow very seldom do you encounter in the world a man of great abilities, acquirements, experience, who will unmask his mind, unbutton his brains, and pour forth in careless and picturesque phrase all the results of his studies and observation; his knowledge of men, books, and nature. On the contrary, if a man has by any chance an original idea, he hoards it as if it were old gold; and rather avoids the subject with which he is most conversant, from fear that you may appropriate his best thoughts.
Benjamin Disraeli