The John Lewis commercial has come early this year. Simon Curtis's take on the creation of Winnie the Pooh arrives soaked in the same aesthetic that drives that Christmas regular. Never has so much dappled light fallen so gracefully on so many fallen leaves. Never has so much Harris Tweed been plucked so cleanly from so many fresh boxes. Few are the families that gleam with such superhuman luminosity as Domhnall Gleeson, Margot Robbie and young Will Tilston. The John Lewis people can only wish for an idyll this delicious.

There lies the problem. The story of how AA Milne (Gleeson) conceived Winnie the Pooh certainly has an idyll at its core – a few weeks spent minding his son Christopher Robin Milne while his ghastly wife (Robbie) was elsewhere – but the surrounding material is a mass of genuine tragedy and low-level misery. It's hard to connect with that discomfort when you're marvelling at the perfection of the set dressing.

A furrowed, fragile Gleeson does his very best with an unforgivably clichéd depiction of the shell-shocked soldier coping badly with life after the Great War. If you guessed that there was a scene in which he flinches at a popped champagne cork then burst yourself a child’s balloon in celebration (yes, that happens too). Robbie is almost defeated by her struggles with the apparently unbearable Daphne Milne. Following the painful birth of Christopher (the charming Tilston), a doctor tells us that “Mrs Milne was unaware of the mechanics” involved in the process. She proceeds to take her suffering out on the poor wee boy.

A gifted actor who relishes the chance to spark up a room, Robbie fails to make anything other than a monster of Daphne. It doesn’t help that the Australian keeps dramatically shifting from a modern middle-class English accent (which she does well) to contemporaneous, aristocratic Mitfordian (much less successful).

Minor humiliations

A wonderful Kelly Macdonald diagnoses the Milnes’ ills with a vigour that the film’s hackneyed conclusions scarcely deserve. Macdonald plays Olive, Christopher Robin’s nanny. You know how this goes. Olive is not only working class but she is also Scottish and, thus, is in touch with emotions that the upper-middle English snoots will never access. It is she who explains that, in the wake of the books’ success, they have been exploiting a son who never asked to become the “Christopher Robin” adored throughout the world.

Here we get to the fascinating fulcrum of the Milne saga. Imagine if there were a real Harry Potter. Imagine if he emerged at a time when nobody had yet grasped the skin-stripping nature of 20th century celebrity. The film is at its most worthwhile when kicking Christopher through a series of minor humiliations and major inconveniences. He poses with the bear at London Zoo. He has to take on a false persona when talking with his father on the radio. Gleeson and Tilston work beautifully together as their two characters confront unhappy truths about the modern world.

Some grit finally lodges in the film’s smooth machinery when, as an adult, Christopher confronts dad about robbing his childhood.

Bum notes

Such strong scenes can’t quite distract from the picture’s bum notes. Can there really be a person anywhere in the audience who, when Milne eventually sends a willing Christopher to public school, believes this will offer relief from the boy’s debilitating renown? After all, those places have no history of bullying. Right? No unhappy boy was made less happy when forced to fag for Botherington-Johnson. Right? (Sorry if I’ve spoiled that for you.)

For all that, Goodbye Christopher Robin manages to push all visible emotional buttons. A penultimate scene between Macdonald and Gleeson could make a statue cry.

You know. Like the bear and the hare in that John Lewis ad.