In our daily lives we see people who wear a mask in certain situations or in front of certain people and return to themselves only when they feel more comfortable. Young children often do this when meeting new people; they act shy and don't talk much. There are also people who wear a mask to deceive others and make themselves look good in front of important people. Sometimes, when a new boss or teacher is first hired, employees or students try to make themselves look good by behaving differently than usual. There are also dangerous criminals who impersonate others and then try to harm anyone they can using this false identity. This can be seen in many different terrorist attacks, where terrorists have fake passports and pretend to be people they are not in order to enter a country or city. All these things prove that even when we think we know who someone is, we don't know their real personality, and sometimes we don't even know their real personality.