Other people are not here to fulfill our needs or meet our expectations, nor will they always treat us well. Failure to accept this will generate feelings of anger and resentment. Peace of mind comes with taking people as they are and emphasizing the positive.
I know so many who have married in the full expectation and confidence of some one particular advantage in the connection, or accomplishment, or good quality in the person, who have found themselves entirely deceived, and been obliged to put up with exactly the reverse. What is this but a take in?
The fourth (of the four cardinal virtues) is supportiveness: this manifests as service to others without expectation of reward. (Paraphrased: Such service is not a mere conforming to some external rule of behavior, but instead a manifestation of your original nature).
Here is the vicious circle: if you feel separate from your organic life, you feel driven to survive; survival -going on living- thus becomes a duty and also a drag because you are not fully with it; because it does not quite come up to expectations, you continue to hope that it will, to crave for more time, to feel driven all the more to go on.
With every one, the expectation of a misfortune constitutes a dreadful, punishment. Suffering then assumes the proportions of the unknown, which is the soul's infinite.