For generations of children all over the world, the stories of Pooh and his adventures in the Hundred Acre Wood have been a beloved staple, spawning television and film adaptations and a slew of merchandise. But until now little has been known about Milne or the little boy who inspired it all – his son Christopher Robin.

Directed by Simon Curtis, this new film sees playwright Milne (Domhnall Gleeson) struggling to readapt to life in London’s high society after returning from World War I with post-traumatic stress disorder. Hounded by his socialite wife Daphne (Margot Robbie) to produce yet another hit play, he moves his family to the English countryside, hoping to find inspiration.

When Daphne returns to London and their nanny Olive (Kelly Macdonald) is unexpectedly called away, Milne is forced to raise eight-year-old Christopher Robin alone and their once-tense relationship blossoms as he is swept up in the magic of the boy’s innocent world.

After publishing the stories they have created together in a book named after Christopher Robin’s teddy bear, Milne becomes an instant success. Soon the family is caught up in a world of glamorous parties, endless interviews and non-stop photo-shoots – but the fame proves both a blessing and a curse.

Gleeson delivers a strong performance as the well-to-do, polite and softly spoken Englishman who strives to form an emotional connection with his son; at times, it is painful to watch his awkward attempts at childrearing. Milne’s experiences of war left him with a tentative hold on reality, and although he at first found comfort in his stories, his happiness was short-lived.

Robbie is also convincing as Daphne, who is depicted as an unpleasant, fame-hungry woman with no qualms about using her son as a promotional tool.

But it’s young Will Tilston who steals the show as the chubby-faced Christopher Robin – his cheeky smile lights up the screen and he gives a flawless performance as a young boy who is both childishly innocent and wise beyond his years. Later, Alex Lawther stars as 18-year-old Christopher Robin, struggling to reconcile his identity in his father’s book with the man he wishes to become.

Goodbye Christopher Robin is a touching story about family (particularly the bond between a father and son) and identity, but seeing the toll fame took on Milne and his son does take away some of the magic from this much-loved children’s character.