In a contest of wills with a coworker today, you should try to take the more daring and aggressive position. Challenge them to make you believe in what they are saying. Even if you don't feel completely confident about playing devil's advocate, your bravado will go a long way toward letting them know you are a force to be reckoned with. Plus, you will be helping them to grow and communicate their ideas more clearly. Project more power than you think you have.