The Burden of Bistory

"The struggle of man against power is the struggle of memory against forgetting."-Milan Kundera.
History means a systematic and an objective study of the human world, or the world in general in our perspective. It is regarded as objective and scientific discipline. But what is the purpose of history; or what the history/historians are doing. Again what is the advantage of the people in learning history; how they are using the historic knowledge in their life. What are the different ways in which the historians, common man, political &religious leaders uses history. More precisely, how the hi knowledge of history turns out to be a burden for all of us.
History means the collective memory of the whole human race. When I say I remember something, I’m simultaneously saying that I'm forgetting something else. In other words, the process of remember, whether it is personal or the collective, includes the process of inclusion and exclusion. We remember what we wanted to remember, not the exact truth. That is why we forget the most important and most touching events in a flash of a second. That is why we have 'memorable' moments in our life, i.e. we are very selective in his case.
The historians, political leaders, and religious leaders while talking about history are very careful to silence certain facts from history. the Hindu leaders discuss about the Muslim invasion; Muslim leaders about Hindu rule and subjugation; Dalits about the hegemony of the upper caste people, and so on....
why do we talk elaborately about our past; past glories and the persecution in the past. What is the advantage we have in talking about the Vedic period and the severe years of untouchability in the contemporary world why do we carry the burden of history. The communal leaders organise their work not by discussing the advantages we have now but by retelling the problems in the past..Why we are dividing the people by using history.