Before blaming people for letting you down because of some strange and convenient sense of entitlement or expectation, consider how many times and ways you have let them down. Using a ' have no expectation' philosophy is simply a dismissive way of not taking responsibility for your own actions and contributions to a dissolving relationship.
Narcissists live with a chronic sense of entitlement to have life revolve around them & their needs. They expect to be able to invest very little in their relationships but demand to get a high yield in return. The life of a narcissist is truly all about them & that will never change because they see nothing wrong with their attitude or behavior.