Denial

Denial is a defense mechanism in which a person unconsciously rejects thoughts, feelings, needs, wishes, or external realities that they would not be able to deal with if they got into the conscious mind. For example, when people are told that they have a terminal illness and are going to die in a short period of time, the news can be so overwhelming that they enter into a state of denial--they refuse (on every level) to accept that they are going to die soon because it is much too painful to handle.