This film is as much a coming of age story as Lord of the Flies. We start with the last day of a golden summer, one Pooh has spent happily with Christopher Robin, playing from dawn till dusk with him and his other friends. This is like the target audience of the film, children. They spend their early lives playing with their parents, siblings or friends without a care in the world.
Then, Christopher Robin has to leave Pooh, or as we learn later, won't be around all the time anymore. Like a child entering public school, Pooh now has to spend a lot of his time without the person he loves most. Things gradually get more and more complicated. Piglet, Tigger and Rabbit find they are struggling in this "new world", so to speak, without Christopher Robin there everyday. The time comes when they set off into the Great Unknown, without a guide. Though they are out to find Christopher Robin, they are also out to find themselves, whether they know it or not. Owl is essentially handing them their high school diploma and saying "Good luck, get out there! The world is scary so be careful!" How many speeches from principals and valedictorians have we heard that boil down to this?
And so Pooh and friends venture out to find themselves, or who they are without Christopher Robin's help. The child has become a college student, on a similar journey to find themself. They all face the horrors and dangers of the real world, and sometimes feel like they can't go on. They feel lost and on their own, and far from home. They wistfully wish to return to the carefree days when they could just play with their loved ones, but that time is over.
Pooh's honey pot represents his perspective that he needs Christopher Robin in-person and around him to truly "be" with him. This honey pot is Pooh's rock, what he depends on the entire film. When he finally realizes that Christopher Robin is always with him in his heart, he leaves behind the honey pot in the pit, and with it, his assumption that he loses Christopher whenever he can't see them.
In college, though things have changed, the young adult has found who they really are without their loved ones, and realizes that though they can't have them around all the time, they are still with them in their hearts. The end of the film has Christopher Robin and Pooh promising to always be with each other even in this new age that is dawning, just like the young adult as they finally become an adult, and go forward in life.