It isn't necessary for people to understand what you have done for them. You know what you have done for them. Don't expect people understand what you have done for them or appreciate you. People's mind is educated from the first days to process the surroundings as soon as possible. Fast analysis requires meta analysis and during this process, the most important goal is the result and some of the data might be lost. One of the origins of psychological disorders is the expectation and seeing that is not accomplished. This doesn't mean that we make ourselves the slaves for others. Working without expectation doesn't equal to work like slaves and don't consider our rights. But I say, when you do something for the people, don't expect to be necessarily appreciated.