People who deal in levels of false expectation often find it difficult to work in a high degree of cooperation. When you enter into an expectation that someone will behave a certain way or a situation will turn out a certain way or you will get a certain result from your action- and that expectation turns out to be false- you often find yourself expressing disappointment  unhappiness, despair or depression... depending on your emotional investment in the outcome. Expectation is a good area to stay away from. When you just let other be and cooperate with what is, you find your life flowing along much more smoothly.
*please note that I sometimes still buy into expectations and float between the idea that I only expect what I am willing to give. Life's a journey I guess