"My family thought I was dealing with a fear of going to war, but I thought I was drawing something I had already experienced," William said.

William has a new novel out - his fifth - titled Past Life.

"The novel explores some ways we might experience things that have happened before our time on Earth. That is why it is set in two time frames [World War II and not long ago in Sydney]," William said.

If anyone is sceptical about this, watch the Netflix documentary Surviving Death. The sixth episode, titled Reincarnation, features the research of Professor Jim B. Tucker, director of the Division of Perceptual Studies at the University of Virginia.

The episode chronicles the incredible stories of James Leininger and Ryan Hammons.

As a child, James had verifiable past-life memories of being a WWII pilot. Ryan also had verifiable memories in childhood of being a Hollywood extra and talent agent.

William believes he, too, had past-life memories.

"But I didn't want to present it so baldly in the novel. For me it was nothing so granular as many children are able to report.

"It was more that I was strongly drawn to a particular time in history - the German invasion of the Soviet Union.

"I was actually most interested in learning about the German side of things, and that descent into hell by the Wehrmacht still fascinates me."

William grew out of drawing battle scenes at about age seven and began making dioramas of them instead. He then graduated to reading about Operation Barbarossa. "I now find those tomes too frightening and depressing, although I do want to reread The Forgotten Soldier by Guy Sajer.

"It's a really amazing first-hand account of being a teenager fighting for the Germans against the Soviet Union."

Past Life, the novel, is about the intersections between art and life.

The character Anna grows up in a third-storey unit in Parramatta with her adoptive Russian mother Sophia.

Small acts of observation and the art of photography are an escape for Anna, along with the seductive world of gardens and orchards.

"Anna finds comfort in plants, basically. She's not too fond of people. Certain plants, like the elm in her mother's garden and the rows of fruit trees in the orchard she photographs, are links to her past - which is a shattered past," William said.

"As a child in the Soviet Union, her garden and orchard were destroyed in WWII."

William said Anna is attracted to photography, as it "assumes authority in representing the past".

Photography gives the impression of "being factual and pinning things in time".

Anna is trying to piece together her shattered past.

William said the past life theme "refers to the ways the past plays out in the present".

"Just how much the contemporary characters are manifestations of the older characters in the book, I leave up to the reader to interpret. It does not have to be read as a reincarnation story at all, that is only one possible way to read it."

The book is set in World War II because "the scale of that war makes it a past experience we can see still playing out in the present".

The character Friedrich is a novelist whose art and personal life were destroyed by war.

"Through his character, I wanted to show how the external world distorts even our innermost selves. He has to stop writing when he becomes persecuted for his work in the Soviet Union of the 1930s," he said.

"Anna may or may not be Friedrich's daughter. The uncertainty about the status of their relationship is due to the war, which destroys Friedrich's connections to his family even before Anna is born."

Anna's identity is nearly erased by the war.

"For a period of time in her childhood, she lives among bands of orphaned children in the forest, quite a common story from World War II," he said.

She forgets to speak and does not know her name or where she comes from.

"Given the book's assumption that the past plays out in the present, how could an event so monstrous in scale and execution as the German invasion of the Soviet Union not be seen to have current effects? One of the book's characters calls it a scar on our consciousness," William said.

William said the COVID-19 lockdowns have been less destructive to writers than other artists, at least work-wise.

"People are perhaps reading more than ever. The silence, stillness and enforced leisure actually are an opportunity for writers," he said.

He's working on a new novel called Saturation, a logical extension of Past Life, as "the past literally oozes out of the present".