Children love to play pretend, and in the process they learn how to play for real.
It is a wonderful learning and development tool, no matter what your age. If you're having trouble getting yourself to act in a particular way, pretend it first. Soon, the pretending will give way to reality. For example, imagine that your goal is to be a salesperson who regularly exceeds your quota and earns big bonuses and commissions. You would start by pretending that you're a top salesperson, in every action you take.