Two of the most famous fantasy worlds in British children’s literature, Neverland and Narnia, have one trait in common:
The longer you stay there, the more detached you become from your life in our world, while the longer you stay in our world after coming back, the more detached you become from the fantasy world.
In Peter Pan, the longer the Darling children stay in Neverland, the less they remember their old life in London or their parents. Michael even comes to believe that Wendy really is his mother. Yet after they go home, and when the Lost Boys come with them and are adopted by their parents, the boys gradually stop believing in Peter Pan and Neverland, as if it was all just a fantasy game they used to play. Only Wendy really remembers both worlds as real places, but even she starts to to think less and less of her parents in Neverland, until she finally decides it's time to go home to them, and when she grows up, her memories of Peter become less clear than her daughter Jane's dreams of him are before she even meets him in person.
Maybe C.S. Lewis drew some inspiration from J.M. Barrie, because the same is true for Narnia. When the Pevensie siblings become the rulers of Narnia and grow to adulthood there, they come to remember their life in England as if it were just a dream. And the same is true in reverse when they come back to England and become children again: their minds revert to childhood just like their bodies, they forget how to do things they learned as adults in Narnia, and their memories of Narnia become more like a dream too. This is what leads to Susan's fate in The Last Battle: while the others choose to keep believing in Narnia (though it probably isn't always easy for them to do), Susan eventually comes to think it was just childhood make-believe.
Come to think of it, in the Alice books, Alice is more detached from her home as she wanders through Wonderland and Looking-Glass Land than you might expect a little girl to be. In the few times she thinks of her home, her thought is usually that she doesn't want to go back – either because she's lost her sense of identity or because she wants to have more adventures – and the only "family member" she ever misses is her cat. Though of course, she's dreaming, and in dreams you don't always think or feel the same way you would in real life.
All these stories are very interesting to compare to The Wizard of Oz, where Dorothy's entire goal is to get back home and she never stops thinking of her Aunt Em and Uncle Henry.
I wonder if that difference says anything about American culture vs. British culture.