Great expectations lead to great disappointments
High expectations are one of the reasons for disappointments. You might counter that by saying it is the expectation that at first sets our goals. Those goals help us in achieving success. However, it isn’t true. Goals, when set properly, tend to create some of the workflow and milestones and measurable steps in the process.
Expectations can be anything, from anyone, and aren’t always logical as opposed to goals and milestones.