I believed it wasn't possible to reach level 31. But (once more
) the final of the game is only a small part of the whole game. If getting Learning make you reach each level sooner that can be useful even if at end you haven't one more level.
That's theory, in practice I don't know but feel pleasant to pick it up relatively soon and wear when possible items that increase xp too.
EDIT: And about xp, quote that if you abuse of hypnotize/sacrifice that's significant xp lost.