It should also be noted that in character, things usually take time to learn, we're just trusting players to keep track of that aspect of the story for themselves. If the player feels the character can learn Enochian, Mandarin and Swahili in 2 weeks after they find a teach, well, good for them, we're not going to spend time debating it or keeping track of it.
Consider though, that a nice thing which is abused may be taken away.