personality word's origin is the mask and it reflects the idea that everybody plays the role of themselves at the life scene. once upon a time it's believed that people's persona and soul can change with masks and they become an another person. apparently after centuries this belief is still accepted. only a difference: the masks are not concrete, they are abstract and invisible. everyone has multifarious masks and choose one of them from their collection. so they turn into a different person. this is the subject that all of us are agreed.