@leeneia: I never really noticed that element of the plot before. Interestingly, in the Kalevala, Untamo, the orphan's uncle, says that he'll sell Kullervo, the boy, to Karelia, "to the blacksmith, Ilmarinen/there to swing the heavy hammer."

But, as we've seen, that's not what happened.

A similar tale turns up in Alaska, Canada, and Greenland. In this story, the boy is called Kaujjarjak, Quadjaq, and other names, and he usually pounds whale blubber, a similarly degrading job. But he still takes his revenge through bears and a knife still plays an important role in the plot (giving him a knife was one of the kindest things anyone did for the kid).

Knowing that aspect of the story makes this passage,

   -snip-
"Of the youth am I the poorest,
Hapless lad and full of trouble,
Evil luck to me befallen!
I alas! must idly wander
O'er the hills and through the valleys,
As a watch-dog for the cattle!"
-From John Martin Crawford's 1888 full translation of the Kalevala, which is also where the first quoted passage came from

which is Kullervo's lament about his bad situation, more poignant.