Memory of the past is one of the principal criteria for maintaining both individual and collective identity. Memory builds a sense of collective identity trough raising awareness of a community's shared past or coexistence over a period of time. Professor Leszek Kołakowski said: " What is a nation? It is that collective memory that gets across to everyone through school as well as through a range of simple traditions, such as monuments, songs, music, literature, all of which consitute our nationhood. Memory is all that makes us live on a separate whole." Memory develops a group identity by conveying values and perceived as identification signs.