Grade: 4.0/5.0

Most of the time, the elaborate kingdoms we concoct as children don’t survive the voyage to adulthood; the fantasy worlds soon become mere memories, if that. “Christopher Robin” explores a different fate for these universes — what if the imaginary worlds of our childhood still survived without us?

The film opens with the familiar storybook approach of A.A. Milne. Scenes come to life right from the page, repeating the comfortable style of the Winnie the Pooh film familiar to many — 1977’s “The Many Adventures of Winnie the Pooh.” In a crisp opening montage, we find that Christopher Robin (Ewan McGregor), after years of boarding school, combat in World War II and, finally, a hectic job, has little left in him of the creative, rambunctious young boy he once was. It seems, too, that he has forgotten the importance of fun, as he sends his wife (Hayley Atwell) and young daughter (Bronte Carmichael) alone to what was meant to be a family weekend; he insists on remaining behind to work, albeit pressured to by his paternalistic boss Giles Winslow (Mark Gatiss).

Soon, though, his productive alone time is disturbed by a certain stuffed bear. Pooh (Jim Cummings), having lost his friends, has wandered from the Hundred Acre Wood to London to find Christopher and ask for his help. Christopher’s mission to bring Pooh home while preparing for an important meeting the next day soon begins to resemble the madcap adventures he and the bear had in his youth.

One of the greatest strengths of “Christopher Robin” is its visual style. The London that the Robins inhabit is a coldly beautiful midcentury nightmare, full of imposing buildings and armies of well-dressed professionals — it’s the phrase “grown-up” in a city. With this form of London awash in dark grays and maroons, the Hundred Acre Wood becomes all the more verdant and idyllic. The creek where Christopher and Pooh played Poohsticks babbles brightly over shining pebbles, and Pooh’s “thinking spot” lies before a stunning hill of jewel-toned trees. In seeing the sheer splendor of the world that Christopher has left behind, we understand a bit more about just how much he has lost in adulthood.

McGregor’s organic performance evokes the playful sparkle that laced Milne’s novels and the original film. His tension as a career-driven patriarch never feels overwrought, nor does his initial vexation with the friend who, even in the best of times, is a “silly old bear.”

Soon, Christopher returns to the Hundred Acre Wood and finds more of his childhood friends, who are more prone to mistrust this strange adult. As he fights to earn their trust back, McGregor allows just the barest flickers of whimsy to crack through his dour facade until a heartwarming first-act climax proves that the adventurous young boy was never completely gone. His performance, in turns childlike and serious, saves the film from the potential melancholy of its premise.

“Christopher Robin” falls into the easy comic rhythm of its predecessors, its dialogue peppered with in-jokes so that it slots naturally into their canon. The film wisely never lingers for long on the gag of stuffed animals coming to life when they clearly shouldn’t. This choice leaves plenty of time for subtler and more unique moments of humor — such as Pooh’s assumption that Christopher’s boss is not really a man named Winslow but rather a woozle, an infamous monster of the Hundred Acre Wood mythos.

In the end, “Christopher Robin” isn’t a denunciation of adulthood, but rather a reminder of what brought us there. Childhood doesn’t necessarily have to disappear to give way to adult life. Miles away from London, even as Christopher has grown older, the Hundred Acre Wood is still thriving — Piglet is still collecting haycorns, and Owl is still boring his friends with his pseudo-intellectual tangents. Once Christopher allows his childhood into his adult life, his entire existence blooms into joyous color. “Christopher Robin” rekindles our own childish exuberance and tells us that perhaps letting some of it back into our lives wouldn’t be the worst thing in the world.