"What is learning? In Wittgenstein's view it has something to do with the traversability of language-games." This strikes me as right. (You also touch on what we might call education as indoctrination, but let's come back to that a little later.) The ability to move from one language game to another requires imagination. In my vocabulary, the term imagination has both aesthetic & moral valences. It is imagination that holds language together, but of course imagination is to some extent a linguistic process, so we have the Gnostic symbol of the snake with its own tail in its mouth. Language, as you say, is fragile, but also strangely powerful & resilient.