Amnesia is a primitive, self-preservation mechanism, which comes into play when man need to protect himself or herself from some form of severe emotional or physical trauma. Man, subconsciously, blocks out the pain of the emotional or physical trauma, by burying the event or events so deeply that he has no memory of them.
In severe cases, the individual not only loses his or her memory of past, painful events, or periods of time, but also loses his or her identity. He or she believes that the events that led up to this memory loss, occurred to another individual, and assumes a new identity. Though he or she functions within societal boundaries, this individual lives only in the present, and has no recollection of the past.
Recoveries, and recovery times, vary from person to person, and either occur instantaneously, or with the assistance of a psychiatric specialist. The amnesiac, fortunate enough to overcome this condition, however, has no memory of the events that transpired when he or she suffered the memory loss.
One must keep in mind that amnesia uncommon, and is not the "normal" reaction to emotional or physical distress. Common reactions to emotional pain, such as fright, stress, hurt, and anger, are dealt with in ways such as bursting into tears, breaking into a cold sweat, or blushing like a new bride.