The first one is: We must study History to know our rich culture and heritage. We must feel proud of our culture and heritage to build our future in a proper manner.
The second reason is: We must study History to learn from our past mistakes, so that we don't repeat these in future.
Caution: Explosive. Handle with care.
'Knowing others is wisdom, knowing yourself is Enlightenment'- Lao Tzu
A blunt knife or rusted knife can't be useful for anything just for the sake we call it as the knife similar to PayTM series or Sachin or Virat records.
It is very true that we should not be bogged down by our past and its reminiscences too much otherwise we will not be able to concentrate in our work presently.
Learning from past mistakes is a mantra which no one should ignore.
Regarding the cultural beliefs and heritage it is individual wish to pursue them or believe them. That way our hindu culture and religion are quite liberal.
Knowledge is power.
'Idhuvum Kadandhu Pogum "
Even this challenging situation would ease
As aptly told by Partha Kansabanik, we should know history to know about the culture and mistakes done in the history can't be repeated.
Yes, we should try to forget those episodes as early as possible and prepare for our life for further struggles and challenges.
I agree that there is no use sticking to the past however horrendous or glorious it had been.
Thoughts exchanged is knowledge gained.