How does the movie teach us about the past and lessons to be learnt for the future?

This is only a short-answer space but I can give you a few ideas. Australia's past in dealing with residential schools was insidious. The government wanted to breed the aboriginal out of half caste or mix race people. Residential school was essentially a prison for native Australians where they were indoctrinated into "white" culture. This was a past that must never happen again. Hopefully cultures can be ome inclusive and celebrate diversity in the future.