This was one of my favorite movies as a kid. Loved the book, too, but found it meandered a bit much and got too deep into the puns / allegories. The movie hit all the important points, quickly.
More importantly.... the whole character of Milo is just very arresting, especially when viewed as a survivor.
Milo is gloomy, withdrawn, and pessimistic, isolated from other kids and with no sign of any family (Wikipedia matter-of-factly notes that this 14-year-old boy lives completely alone). He sees nothing worthwhile in the world and just trudges through life, unsatisfied everywhere. We're given no indication of what really caused this. His themesong wonders at it for us....
"What's to become of Milo?
What will he grow to be?
When he looks at life and he doesn't see
Doesn't see the bright blue sky
Doesn't hear the train go by
Doesn't see the song
Little fellow, what's wrong?
What's to become of Milo?
Lost in a vacant stare
Doesn't have a dream
Doesn't even care...."
After making his first real friends and going on a quest to restore "rhyme and reason" - making peoples' words make sense, putting an end to chaotic noise, and learning time and again that people aren't always what they say they are.... Milo returns to his life, with a newfound sense of value, gratitude and purpose.
"Milo, open your eyes
Look around you and see
See how wonderful life can be...."
It just makes me feel good to watch it, the animation is beautiful and most of the songs are good for your mood as well.