It's hard to end a story, and the demands of the journey motif -- home; leaving; island; return; home -- must have been too hard to resist; but the film would have been better if we had been left with the anguishing Carol howling on the beach as Max sails away (not quite this image, but it's the closest I could find).
The story's about growing up, yes; and so the ending brings Max home to indicate that he's learned about civilized life from his venture into the wilderness (that is, grown up). But I think it would have been better to let us stay in the realm of the imagination. For me, the film was about the imagination: about how a child -- a human -- uses storytelling, fort-building, games (even violent ones) to understand life.
Keats' Nightingale ode is a place I go back to, to remind myself of the imagination. It begins, like Max's story, in melancholy -- "Here, where men sit and hear each other groan." This grieving poet -- his brother recently dead, his own life deeply uncertain -- "runs away" from home to join the singing of the nightingale, the imaginative power that cuts across time, limitations, categories. He revels in its joyful abandon: "Already with thee! tender is the night. . ." But, as with Max, escape into imagination is no simple walk in the woods; it takes the melancholy and intensifies it until the dark woods become almost a grave:
I cannot see what flowers are at my feet,"Darkling" -- in the dark -- he listens, "and for many a time / I have been half in love with easeful Death." All vision gone -- that most rational of senses -- the imagination "guesses" at truths that the conscious mind doesn't find. Time ceases to mean anything, the seasons blend together, the generations meld with each other, until windows open on another, strange land:
Nor what soft incense hangs upon the boughs,
But, in embalmed darkness, guess . . .
. . . magic casements, opening on the foamThis could be Max's island with its "perilous seas" and its deeply forlorn creatures.
Of perilous seas, in faery lands forlorn.
Keats wrote in a letter once about how Milton put the imagination to reality in Paradise Lost: "The Imagination may be compared to Adam's dream--he awoke and found it truth." But at the end of the nightingale, Keats is far less sure of that truth: he wakes, not to truth, but to doubt, back from the bird's song "to my sole self," to that rational curse of consciousness and identity. "Fled is that music." Maybe in all romance narratives, we have to return from the quest, come home, wake up; but hopefully we can remember the journey, the island, the bird's song, that deep "ecstasy" -- or "wild rumpus" -- that reminds us of the transforming power of the imagination.