
                           when i went to the design school while ago, we had project that
                           chose one of the emotion ( anger, sadness, happiness, fun )
  
                           one of my friend drew beautiful design then all of the classmates thought 
                           it represent sadness but she told us it was anger.
                            and She said anger feeling similar with sadness for her.
                             When I heard that it was new angle for the feeling and i thought she was right.
                            because when i feel anger i feel sad as well.  I think many people get mad 
                            because feeling sad about something.   
                           anyway, how do we know what do we feel?