Yes, but you can't dissociate the pain from the healing effect. In that sense, it is enforced. And this is typical for pain: either it comes by accident, or as a side effect of something which outweighs its unpleasantness. Most of people with pain, even if they endure it voluntarily, didn't choose it because of the pain itself, and would prefer the pain go away. Norwegians, on the other hand, eat lutefisk exactly because it is lutefisk.

Note: in fact I don't know much about Norwegians. Perhaps they eat lutefisk because of the force of traditions and hate it actually - but if so, I would have much less difficulties in saying that lutefisk is indeed bad.