The ever-so-English charms of “Goodbye, Christopher Robin” aren’t spoiled by its abrupt shifts in tone and occasional sentimental cheats. But those failings do tend to render this Simon Curtis film about the little boy and his toys who inspired “Winnie the Pooh” into weak tea.

It’s a painterly picture of “England’s green and pleasant” woodlands, the area in Sussex where young Christopher Robin Milne played in his “Hundred Acre Wood.” The little boy playing him is an adorable English moppet, and the omnipresent Domhnall Gleeson (“American Made,” “The Wingman,” “The Revenant”) makes a properly droll, reserved and Great War-scarred A.A. Milne.

But so much of it plays like Brit-pop Psychology 101, from the closed-off dad and not-that-interested-in-her child flapper mom (Margot Robbie) to the Scottish nanny, played by Kelly Macdonald, who has played more women “in service” than a beauty of her talents should have had to. There’s the flip, light writer of stage comedies who only wants to write the serious book “that will prevent another war,” and the too-pat “Pooh’s name came from here, here’s who thought up “Eeyore,” here’s where “Piglet” came from, “Tigger,” etc.

Alan Alexander Milne has returned from the Great War trenches to his posh life and oh-so-posh wife (Robbie, of “Suicide Squad”) and publisher eager for him to get back to the business of writing humorous poems for “Punch” magazine, and making comedies like “Mr. Pim Passes By” for the stage.

But Milne (Gleeson) is haunted by what he saw in the World War. He is enraged at his class for its role in the slaughter, “for what?” It’s just that he’s stereotypically British upper class in his emotionless sharing of those experiences.

“I was at the Somme. It was a bad show.”

He isn’t “ready to put a smile back on our faces,” which disappoints his publisher and annoys his wife, Daphne, who can’t understand why he can’t just “get over” it all.

“You know, if you don’t think about a thing, it ceases to be true.”

She has a baby to please him, and never lets him forget the burden that was. She even agrees to move to the country to get him back to work.

But the little boy (Will Tilston) that their nanny (Macdonald) is raising for them captures his interest. Not right away, and no, the adorable child his mother insists on dressing in smocks (she wanted a girl) doesn’t melt his heart. But “Billy Moon,” as his parents call him, as wary as he is of his remote, stern and somewhat disturbed father, has this vivid imagination.

And when they’re forced together due to childcare issues, the tot with the stuffed bear, piglet and donkey enlists his emotionally unavailable dad on a healing tour of his world of nature and fantasy.

“Let’s be hunters in the snow!”

The script stumbles in making that transition from father-son bonding to best sellerdom. That’s because real events didn’t happen quite that abruptly. Milne started finding success with children’s verse before turning “Pooh” into an international icon, and his little Christopher Robin into “the most famous little boy in the world.”

“Goodbye, Christopher Robin” has an ungainly structure that suggests drastic editing, a father’s guilt over “using” his son to get rich and famous, a mother’s fearful mistrust of “boys” because of the trauma of not knowing if her best boy, her husband, was going to return from the war and her certainty that another war was coming for her son (treated as an afterthought even though it frames the story).

The adults don’t really reach out to us, as characters or performances. Too calm. Too insistent on just “carrying on.”

But there’s something almost ancient about Winnie the Pooh, something that resonates on a primal childish level, and “Goodbye, Christopher Robin” gets at that via the child who inspired him.

The film manages to move and touch us, revealing that the books are timeless due to their exquisite, English craftsmanship, their wit and warmth. Learning they were created by a troubled, serious father trying to capture the carefree mind of a boy who found escape was as near as a stuffed bear and another trip to Pooh Corner does nothing to ruin that. Not at all.

MPAA Rating: PG for thematic elements, some bullying, war images and brief language

Cast: Domhnall Gleeson, Margot Robbie,Will Tilston, Kelly Macdonald, Alex Lawther, Stephen Campbell Moore

Credits:Directed by Simon Curtis, script by Frank Cottrell Boyce, Simon Vaughan. A Fox Searchlight release.

Running time: 1:47