“They say never work with children or stuffed animals,” jokes director Simon Curtis in a chat during the Mill Valley Film Festival.

The director does both in Goodbye Christopher Robin, the story of how British author A.A. Milne came to create Winnie the Pooh and friends in the years following World War I.

Played by Domhnall Gleeson—who is seemingly everywhere this fall with roles in Mother!, Crash Pad, and American Made, and returning to the character of General Huck in Star Wars: The Last Jedi—Milne is at the outset of Goodbye Christopher Robin a veteran of the Great War suffering from what was then known as shell shock. A member of the upper crust, he finds reintegrating into the social whirl impossible. Relocating his family to the English countryside frustrates his wife Daphne (Margot Robbie), but it is that decision that paves the way for Milne’s classic children’s stories.

In Curtis’ mind, Daphne is in many ways the key element in the creation of Pooh. She was the person who bought the stuffed bear and other animals, giving him a voice as she played with her son.

“That joy on her face when she hands him the tiger for the first time, that’s one of my favorite moments in the film,” Curtis says.

At the same time, she inadvertently sets the stage for Pooh’s creation when she leaves her family to spend time in London, little realizing that Christopher’s nanny Olive (Kelly Macdonald) would be called away at the same time.

“She’s doesn’t act like a modern mother, but she does act like a mother of that time and of that class did, which was to make sure there’s a great nanny looking after the child, and then live her own life. That’s what she does,” Curtis says.

It is in being left alone with eight-year-old Christopher (Will Tilston) that Milne finds inspiration along with discovering the fun in playing with his child. As they roam the forest around their home, Cotchford Farm, with the boy’s stuffed animals in tow, Milne’s imagination comes alive and he also begins to find a kind of peace that has eluded him since the war.

“The sequence where the father and son play together and you see the joy on their faces [is a special moment],” says Curtis. “Both Domhnall and Will rose to it so perfectly. Domhnall is an extraordinary man and an extraordinary actor, first and foremost brilliantly intelligent.  He had to travel a very long way to play this, because he’s a very gregarious, modern Irishman playing this very particular man. The character holds back, but he opens up and the joy he has with his son is one of my favorite things I’ve ever done.”—Pam Grady