Bob Graham's prize-winning picture book Home in the Rain began as a smudge of pastel colour on a piece of copy paper. "It turned out to be a skyline of hills and then I put some dark cloud over it," he said.
"I put some trucks on a freeway in there and I decided to put a red car, which looked quite vulnerable in the circumstances, and lots of rain, and I went on from there.
"I kept asking myself questions and I'm thinking who are the people in the car, they are on a journey obviously, they are going from here to there, I knew that much and for the rest I just stuck in there to see what was happening myself. It's like dropping a stone in water and watching the circles spread out.''
From smudge to final draft, Home in the Rain took eight months. On Friday the heart-warming tale that takes place on a freeway next to a petrol bowser was named the Children's Book Council of Australia's Picture Book of the Year.
It was the Kate Greenaway-winning author-illustrator's seventh such honour cementing Graham's formidable reputation as an Australian master storyteller.
In a strong year where friendship and family were the dominant themes, top honours for older readers went to Claire Zorn's One Would Think the Deep, which captures the grief and anger of 17-year-old Sam following the unexpected death of his mother and how he learns to move on.
Zorn started from "probably the most unlikely place to find inspiration for a novel: it was a Red Bull commercial".
"I first saw it in a cinema," she said. "It features one of my favourite pieces of music by Sufjan Stevens accompanied by beautiful images of extreme sports. I'm fascinated by things like surfing, snowboarding and skateboarding. I find them to be so beautiful. Like ballet - I could watch it for hours."
Other winners included a scientist (Gina Newton), a street artist (Van T Rudd) and a radio producer (Johanna Bell).
The Eve Pownall Award for information books was won by Newton for her identification guide to Australia's diverse fauna in 55 national parks while best book for younger readers went to Trace Balla for her graphic novel of a hike into the Grampian wilderness.
The prize-winning books were chosen from a pool of more than 400 entries. Former Australian Children's Laureate Jackie French entered a record five times.
Margot Hillel, the council's national chairwoman, said the 2017 winning and honour books demonstrated why "our creators are so highly regarded around the world, with beautiful prose, delightful illustrations and fascinating topics that are sure to delight generations of readers".
Since writing and illustrating his first picture book at age 40 - "it wasn't a career move or anything, it was a good idea at the time" - Melbourne-based Graham, 73, has collaborated or created 90-odd books.
"I sit her in disbelief at that. That very figure exhausts me."
Graham's stories don't call on childhood memories but arrive from "what I see around me when looking out the front window to the street and the movement outside my front gate".
He's learned to trust his intuition and "not question it too much". "As far as I can describe I have no formula other than taking small events and seeing what the outcome might be. In Rain I put those two people in the car because it seemed right for me at the time.
"As a kid I wouldn't have believed I'd be at home drawing and writing words and stories all day. The other day I spent the whole day drawing a hedgehog skipping rope with a mouse, how good is that?"
THE 2017 BOOK OF THE YEAR AWARD WINNERS
Book of the Year: Older Readers
Winner: Claire Zorn, One Would Think the Deep, University of Queensland Press
Cath Crowley, Words in Deep Blue, Pan Macmillan Australia
Zana Fraillon, The Bone Sparrow, Hachette Australia
Book of the Year: Younger Readers
Winner: Trace Balla, Rockhopping, Allen & Unwin
Honour Books: Wendy Orr, Dragonfly Song, Allen & Unwin
Kate and Jol Temple/John Foye, Captain Jimmy Cook Discovers Third Grade, Allen & Unwin
Book of the Year: Early Childhood
Winner: Johanna Bell/Dion Beasley, Go Home, Cheeky Animals!, Allen & Unwin
Kylie Dunstan, Nannie Loves, Working Title Press
Leila Rudge, Gary, Walker Books
Picture Book of the Year
Winner: Bob Graham, Home in the Rain, Walker Books
Honour Books: Lance Balchin, Mechanica, The Five Mile Press
Van T Rudd/Maxine Beneba Clarke, The Patchwork Bike, Hachette Australia
Eve Pownall Award for Information Books
Winner: Gina Newton, Amazing Animals of Australia's National Parks, NLA Publishing
Honour Books: Jennifer Cossins, A-Z of Endangered Animals, Red Parka Press
Lorna Hendry, The Gigantic Book of Genes, Wild Dog Books
Crichton Award for Debut Illustrator
Winner: Van TRudd, The Patchwork Bike, Hachette Australia