I've always been obsessed with words, and the choice of words in stories. I'm currently reading Splintered Light, and this has ramped me up even more than usual.
So, I am currently wondering - in the book, when Frodo says, "I will take the ring to Mordor, though I do not know the way.." if he is really talking about geography, or at least not just about geography. I think when he says he does not know the way, he doesn't mean the way to Mordor... he means he doesn't know the way to accomplish this task; he does not know how.
Learning the directions would be fairly simple, and he should be able to find out before they ever leave Rivendell.
Frodo doesn't know the way to Mordor at the council of Elrond, October 26. He has 2 months to look at maps, get council, etc. before they leave Rivendell, December 26. (There is no "which way, Gandalf?" nonsense in the book). They spend an entire month in Lothlorien. He does not split from the fellowship until February 26.
It's easier to believe he learned about the route than that he didn't.....
(I'm using the dates as they are in the tale of years, not trying to shift them...)
Learning "the way" to carry the ring to Mordor is a very different task, and Frodo is trying to learn it every single step of his journey.
In Splintered Light, Verlyn Flieger says:
We do not truly understand a text until we understand the words not only as they are currently used but as they were used in the time in which they were composed. Only with this understanding is it possible to touch the mind of the author and of his first audience, to bridge the temporal distance (whether short or long) between that time and the present.