It is not easy to live with an enlightened person, or rather it is so easy that the ego finds it extremely threatening. Remember that the ego needs problems, conflict, and "enemies" to strengthen the sense of separateness on which its identity depends. The unenlightened partner's mind will be deeply frustrated because its fixed positions are not resisted, which means they will become shaky and weak, and there is even the "danger" that they may collapse altogether, resulting in loss of self.
— Eckhart Tolle