When someone lets you down or chooses to disagree with you, your anger, your grief, arises from their behavior. Or so you believe. But if you observe your thoughts closely, you will find that it is your mind that rushes off immediately to demand: ā€œHow dare they treat me like this?ā€ So, essentially, it is your expectation of that person, that they must behave in certain way that is causing you agony. Just drop that expectation. And you will not have any suffering on account of anyone or their actions anymore. Herein lies the secret to remaining unmoved, detached and dispassionate about what others are saying or doing to you. This is the way you protect your inner peace and happiness.