*gasp* "Mistakes? What mistakes?! Lotr is PERFECT and absolutely FLAWLESS!"
Look, I love love love the books. They are indeed nearly flawless. The world and lore is so deep and rich. Heck, I arguably know more about the history and geography of middle earth than the real world. It's great and deserves every bit of praise it receives.
That said, there are a handful of places where I disagree with the choices JRR made. These instances are supremely rare. In fact, most apparent "mistakes" aren't really mistakes and are the product of ingenious storytelling and they make sense upon further readings and reflection. There are, however, a couple times where I disagree with the choices he made.
One such instance for me is how long it takes for Frodo to leave the Shire. You've just been informed that essentially Satan himself wants HIS ring that you have and he's looking for you. It could mean death and torture for you and the destruction of the Shire. I know! Let's take a year to leave! Let's take our time selling our house and settling our affairs. Idk, this to me is a mistake and hurts the dramatic effect, tension, and lowers the stakes when they should be raised.
This isn't a movie vs book thread but in this regard this is one tiny area where the movie improved the story. Idk if Frodo needed to set out that night, but to wait a whole year? Nah. It doesn't work for me.
This is one plot point where I have yet to see a Tolkienphile manage to explain how his choice of a leisurely flight from the Shire actually makes perfect sense. Please, I welcome it!
What are some other places you think JRR might have made a "mistake?"
I think an argument could be made that the danger seemed less pressing than it in fact was. For instance, Gandalf, being in the Shire at the time, was unaware that Sauron had finally decided to unleash the Nazgul, sending them across the River to hunt for the Ring in June.
There are other reasons, but I'm curious where the idea of a year's wait comes from. Gandalf's "last test" was made on April 13; the decision to leave around September 22 was taken "a few weeks" later. As soon as Gandalf learned the Nine were abroad, he took steps to warn Frodo to leave the Shire as soon as possible. Had he not been imprisoned by Saruman, he would have gone there himself, and did so when he escaped. But even absent all that, the actual elapsed time from decision to departure was only four months.