In the little boy's heart, happy as he was, there remained a vague ache.
How can you miss something, someone, you never knew? But he had the dog - tag.
That would do.
That brought him close.
He took to wearing it in early teens -- and tried to engrave his own name on its reverse side using the sharp point of a drawing compass, perhaps somehow to join himself with the missing owner.
I can see those marks as I hold it in my hand today.