This flaw is only applicable for monsters with a strong mundane identity, that somehow transforms between mundane and monster form. It implies a strong opposition between the monstrous and human side of the personality.
Whenever you lay off your "wolves clothing", you suffer some trauma. You tend to fall asleep or collapse, and your memories of what transpired wen you were in monster form are often hazy and uncertain. In many cases, they will be mistaken for dreams.
Creatures with this flaw thend to have schticks like Transformation or FalseImage to effect their change.