Complaining is one of the ego's favorite strategies for strengthening itself. Every complaint is a little story the mind makes up that you completely believe in. Whether you complain aloud or only in thought makes no difference. Some egos that perhaps don't have much else to identify with easily survive on complaining alone. When you are in the grip of such an ego, complaining, especially about other people, is habitual and, of course, unconscious, which means you don't know what you are doing.
— Eckhart Tolle