I was about 15 when I saw the film Picnic at Hanging Rock. My aunt – my dad’s sister – took me to the cinema in Griffith. I could probably have counted on one hand how many times I had been to a movie; there was never any money spare for luxuries like this. I don’t know why she took me and I don’t know why to this film. But it was a rare treat, Jaffas and all. Beyond that was the film itself, and how it reached inside me and left me pondering questions that I have spent a lifetime trying to answer.

It was the music that grabbed me first, those pan pipes eerily floating over that parched Australian landscape. The film seeped into my consciousness. It was as much a dream as a film; it unnerved me. I didn’t make the connection at the time – not intellectually at least – but I was left feeling as if the world itself had turned. This was about who we are as Australians; who we are in a place that is profoundly unsettled.

I can see now what I could not see then: this is a dreaming story – not white, not black – it is a dreaming for an Australia still becoming. This is a story of initiation: a profound rite of passage. It is a haunting meditation on place, with the vanishing girls seemingly swallowed by the land itself. Remember the voiceover of one of the doomed girls: “What we see and what we seem are but a dream … a dream within a dream.”

The girls, when they disappeared, became part of the rock itself. There is something deeply Hegelian about it all. How strange that the dreaming in an ancient land could connect with a 19th-century German philosopher. But Georg Wilhelm Friedrich Hegel spoke of becoming: he spoke of man “not being at home in the world”. Picnic at Hanging Rock has always struck me as a film about what Hegel would have seen as our inevitable process of change.

Peter Weir’s film, perhaps even more than Joan Lindsay’s novel, revealed the incongruity of imposed Britishness on a harsh, hot, foreboding place: Europeans trying to tame an untameable country. Weir’s camera focuses on an army of ants, or dwells on the light peering through the branches of a tree. He allows the wind and birdsong to punctuate the silence. In this way he grapples with the themes of alienation and belonging.

‘A dreaming for an Australia still becoming’: Peter Weir’s Picnic at Hanging Rock. Photograph: n/a

The Indigenous presence is felt more than seen: the land itself represented as blackness.

This is what shook me at Lake Mungo, that ancient place of old bones; it is what haunts me when I go back home and stand by the Murrumbidgee River, gazing at the stars.

The British-Indian writer Salman Rushdie once said of the importance of stories: ‘Those who do not have the power over the story that dominates their lives, the power to retell it, rethink it, deconstruct it, joke about it, and change it as times change, truly are powerless because they cannot think new thoughts.’

Photograph: HarperCollins

As our world spins around us, consumed as we are by political upheaval, economic uncertainty, terrorism and war, I have wondered about this thing: story and its importance. What is this great story of us? What captures this thing of life? This transcendence; this beauty and terror; this hope and despair; this fleeting performance measured in minutes before the curtain falls and we fade into the black and others mount the stage.

We all seek identity: which communities we belong to; which football club we follow; what music we like; how we dress; where we live; religion; race; culture. All of this gives us a sense of who we are, somewhere to belong. But there is a darker side to identity, a stifling conformity; an us and them; identity that pits us against each other. It keeps returning me to that question: am I Australian? Am I Aboriginal? Can those things be the same?

I am an Australian – yet my history tells me that my sense of citizenship and belonging is fragile and fraught. I belong to a nation; I belong to family and a people and yet I am an individual free to determine for myself who and what I wish to be. But how do I do that? I am an individual – I value that fiercely. Yet the freedom to choose was taken from me when Australia had already settled on what I was: black, a half-caste, an outcast; I was not born into Australia. My identity was already determined and I have spent a lifetime working my way free.

To be Aboriginal must I reject Australia? To be Australian must I put aside history? Must I forget? History and justice, these are ideas that in the past years I have returned to again and again.

Stan Grant: ‘I am an Australian – yet my sense of citizenship and belonging is fragile and fraught.’ Photograph: Kathy Luu/HarperCollins

This is not my story alone, it is the story of Australia. It is what our great storytellers have wrestled with; how can we belong in a place so foreign, so strange? When a nation is founded in a great injustice – and a great injustice it remains, taking someone else’s country – how do we find rest? How do we find peace? Thomas Keneally, in his book The Chant of Jimmie Blacksmith, imagines a scene long after the whites have come. Keneally’s Jimmie Blacksmith emerges as a new type of being, a creation possible only here. The bone-pale face of the white stranger has darkened, and the curly hair of Dark’s Bennelong has straightened. This is the Australian synthesis: Blacksmith born of black and white – from ancient and new – Australian in a way that no other can be.

Keneally’s Blacksmith was based on a historical figure, Jimmy Governor. The real Jimmy was a mixed-race Wiradjuri man who, like his fictional equivalent, married a white woman and searched for a place in this new country, on the eve of Federation. Governor found instead derision and rejection, his wife endured humiliation, and Jimmy – aided by his brother and an uncle – responded with a violent rampage that ended with nine people dead and sparked the biggest manhunt in Australian history.

Keneally sees his Jimmie as the man between, finding a place in neither the white nor black world. He is a potent symbol of a country in transition; what has been and what is to come. In film and art and song and literature we have sought to make sense of what it is to be this thing called an Australian. Tom Keneally and Peter Weir: they have tried to tell the story of us – of our place. They set us in an ancient continuum ruptured by a cataclysmic clash of culture and civilisation. Out of destruction we are born anew: uncertain perhaps of our place, but with no other place to call our own. Whiteness must struggle with its blackness; it is in the land itself, it is in the memory of the people displaced. And it is there in our blood: hidden blackness, or blackness denied.

Tommy Lewis as Jimmie in Fred Schepisi’s film version of The Chant of Jimmie Blacksmith. Photograph: TCD/Prod.DB/Alamy

Those of us who identify as Indigenous, as First Peoples, we too grapple with our whiteness. It is there in our skin; no longer black but lighter now. Sometimes, we are indistinguishable from any other white person. For us it is about fashioning or refashioning what it is to belong, when the very essence of belonging has been ruptured and the certainty of heritage blurred. Jimmy Governor (Jimmie Blacksmith) is part white, married white and yet is rejected for being black. What it is to be Indigenous has become a puzzle not easily explained, nor simple to comprehend. These are questions I am left to ponder as well.

As modern Australia celebrated its birth at Federation in 1901, the historical inspiration for Jimmie Blacksmith, the real Jimmy Governor, sat in a Darlinghurst jail cell, alternating between singing songs in his traditional Wiradjuri language and reading the Bible – the synthesis of the old and new worlds that collided here so violently, given form in a man soon for the gallows. It is a synthesis Keneally saw as contradiction; and yet it is the essence of being Australian.

Joan Lindsay wrote the book of the missing girls of Hanging Rock, and director Peter Weir fixed it in our imaginations. The land itself, a potent character in an ethereal tale of place and being.

These are Australian stories, ancient and modern, and all efforts at recognition – a need to be seen. It is indeed a fleeting project, an attempt to capture a people – a people always changing – in a time and place. A drawing on a cave wall preserved for antiquity, to tell future people: “This was us.” It is so human, and it is essential.

• This is an edited extract from Australia Day by Stan Grant, out now through HarperCollins Australia

