Knowing the age of the person you are talking to is very important for the Japanese. It lets them use the appropriate style of speech depending on the age of the person they are addressing. Respect and humility plays an important part in the Japanese language.
We play a different role with others – parent, spouse, friend, colleague, teacher, student, stranger, and a bystander – innocent or otherwise! The multiplicity of roles hides our true self. We choose what we speak and the way we speak depending on whom we are speaking to and also on who is present in the audience. We are a different person at home and perhaps another at workplace.
Children who are aggressive at school are often not so aggressive at home and vice versa. The language we speak with our friends is very different with others. While this may be less noticeable in English-speaking countries from a language perspective, the underlying demeanor and style does vary.
It is said the best way to judge a person is to see how he treats his servant in front of others! This is entirely due to the fact that we are a different person with every different person. Human beings have evolved in a very complex manner and the chameleon in us is very active. We wear a different garb within ourselves and without. We hide behind our facade and our masks.
Internet too has also enabled this. We now have profiles for every account. You can have avatars and this need not match with who you are or what you are. We can decide what should be made public and who will see what portion of you. While many privacy issues are at stake here so also is the fact that the real you is becoming fuzzier day by day.