Very applicable to trading:
Henry Ford agreed:
“None of our men are ‘experts.’ We have most unfortunately found it necessary to get rid of a man as soon as he thinks himself an expert because no one ever considers himself expert if he really knows his job . . . Thinking always ahead, thinking always of trying to do more, brings a state of mind in which nothing is impossible.”
via What Steve Jobs, Thomas Edison, and Bob Dylan Have In Common | The Blog of Author Tim Ferriss.