Expectations are funny things. They’re little predictions, and may or may not be accurate for any number of reasons.
When we predict correctly, we get to assert just how smart we are. An incorrect guess may cause as little as temporary denial, or full-blown depression.
When you let go of expectations, you free yourself up to live in the moment. To be honest and understanding, and not dependent on your rightness or wrongness, alleviates that moment when the expectation is either realized or proved incorrect.