To me its a story about becoming, recognizing identity, even if you don't have the words to know.
Here's the passage I like. That visceral recognition from your very soul without even knowing what they are.
One evening, just as the sun set amid radiant clouds, there came a large flock of beautiful birds out of the bushes. The duckling had never seen any like them before. They were swans, and they curved their graceful necks, while their soft plumage shown with dazzling whiteness. They uttered a singular cry, as they spread their glorious wings and flew away from those cold regions to warmer countries across the sea. As they mounted higher and higher in the air, the ugly little duckling felt quite a strange sensation as he watched them. He whirled himself in the water like a wheel, stretched out his neck towards them, and uttered a cry so strange that it frightened himself. Could he ever forget those beautiful, happy birds; and when at last they were out of his sight, he dived under the water, and rose again almost beside himself with excitement. He knew not the names of these birds, nor where they had flown, but he felt towards them as he had never felt for any other bird in the world. He was not envious of these beautiful creatures, but wished to be as lovely as they.
Based
https://en.m.wikipedia.org/wiki/Environmental_impact_of_concrete