Some individuals have the ability to succeed in their work, but never do, says Ben Stein. Here, he says are some mistakes that keep them from reaching their potential: 1. Not being honest with themselves about their chances of succeeding. They may need more training or more commitment, or a better work ethic, but ignore the facts. 2. Not producing. People get paid for doing something. To get paid more, they have to do something that adds more value. 3. Not appreciating friends. Some people are nice only to those who can advance their causes. 4. Having bad manners and being rude. (Politeness pays) 5. Dressing inappropriately. 6. Having a bad attitude and infecting others with it. 7. Arguing needlessly, thinking it makes them appear clever or smart. 8. Putting first things last. (Setting priorities is an absolute necessity)