“I could not possibly expect the reaction it has gotten,” says Charles Williams. Last weekend, the 36-year-old Australian director’s short film, All These Creatures, won the Short Film Palme d’Or, the festival’s top prize. Williams’ film was one of eight selected for consideration by the festival, from close to 4000 entrants.

Set in the south-eastern Melbourne suburb of Dandenong and filmed on a small budget, the film is a taut and visceral exploration of the struggle of a child to make sense of his father’s fraying mental health. The perspective shifts between the child’s present — feeling strange, questioning, not-knowing — and his reflections as an adult. And the story is a personal one for Charles.

Speaking from France, with his daughter playing in the background, he explains that the story is one that stuck with him. “I couldn’t get out of my head when I was an adolescent myself, that I think to some extent I can’t get out of my head now. The film plays on the immediacy that an adolescent child feels in that situation, about his father and also his own concerns about what he’s going to grow up to become. But then it also plays on what an adult feels looking back on that situation as well.”

The centre of the film is a remarkable performance by Yared Scott, a young Ethiopian-Australian actor, who Williams found after an exhaustive casting process that drew over 400 hopefuls. Charles speaks about how the film came together once they found the right lead. “Once I cast Yared, it became an Ethiopian-Australian story, and I brought on four different Ethiopian-Australian advisers to inform the accuracy of the film, which was terrific, a great experience.”

Speaking of the work that went into the film, Williams is aware that it’s a team effort, “I must have thanked over 100 people in the credits… and they all helped it become what it [ended up] being.”

The Palme d’Or is the highest prize awarded at the Cannes Film Festival, and widely considered to be the most prestigious award in the film industry. The overall top gong this year went to Japanese Director Hirokazu Kore-eda for his feature film Shoplifters, about a family who rely on shoplifting to survive poverty, and American director Spike Lee won the Grand Prix for his satirical film BlacKkKlansman, which tells the true story of a detective who infiltrates the KKK (played by John David Washington).

Williams is one of three Australians to ever win the Short Film Palme d’Or, after Laurie McInnes (Paliside, 1987) and Glendyn Ivin (Crackerbag, 2003); he’s aware of the weight of the award. “It means so much that I can’t even fully process it,” he says, “You know… it’s like a Pulitzer for me as a filmmaker.”

Williams is currently working on two feature films to follow up on his success at Cannes, “I think one’s very big, and I don’t think it’ll happen very soon. But the other one I hope to develop and make as soon as I can. It’s very similar in theme and tone to the short film — it’s a different world, but it’s also a father-son story, and explores that bond.”

What does this kind of international award mean for an Australian filmmaker’s career? “I think it’s a great door opener, and not to be too boring, but I think it’s kind of a responsibility,” Williams says. “I don’t think they just give you the Palme d’Or and tell you congrats and pop some champagne. I think there’s a sense of, or I feel a sense that’s implied, where they say … ‘Look, we only give one of these a year, so don’t waste it. Make great films.’

“It’s kind of a promise, rather than an end-point.”