It hurts when our expectations are not met by others.  When we believe something to be true and hope that others will align themselves with our standards, we set ourselves up for failure.  The most influential aspect of our expectations being met or not met is their attainability.  Attainability of expectations is not based on low-set goals, instead it is relative to the practicality and reasonably of the expectations.  When we set unrealistic goals and expect others to follow such a standard, we fail to integrate reality with expectation.  However, when our goals are based on the reality of our surroundings while developing the future ability of all who attempt to meet such goals, the expectation for others to strive after these goals is not so outlandish. 

Make sure that when you place expectations on other people or a group of people, that you base your expectations on the present state of events, as well as a reasonable goal for the future.  Otherwise, you will never be able to exist within your own paramaters or with the group you expect to follow you.