Who is The Child on the Train from Wind, Sand and Stars and what is their importance?

The golden child sleeping between the peasant worker parents on the train seemed to Antoine like a young Mozart full of potential and promise. The heartbreaking thing to Antoine is the seeming absence of possibility that whatever gifts lie in the golden child would ever be cultivated so that the world may benefit from his presence. The child comes to symbolize the unaddressed potential in whole populations who will be swept out of themselves by the necessity of work and submission to a system that has no desire for their more soulful gifts.