When I was in school I wrote short stories, and I never got lost. It's not that short stories are easy, but because they deal with one incident in one character's life, leading to one moment of realization (or epiphany, as Joyce called it), they are neat, succinct, and focused. There's no room to get lost because only one thing, really, is happening.
Novels, unfortunately, are not just long short stories. They have several major characters in addition to the main protagonist and antagonist, and at least one significant sub-plot. They have falling action, whereas a short story tends to end as soon as the main character has reached their epiphany. And most difficult of all (for me at least), they have much more plot going on in the middle.
All my short stories have been written with pretty much no preparation, and I've always been happy with the result. But you can't really write a "novel" by just plunging into it and hoping for the best. I learned this the hard way with my disastrous first book. The comments I received praised the writing style but complained there was no plot.
Of course, there wasn't. I never bothered putting in a plot for that book. One of the things they teach you when you study literature instead of creative writing is that plot is plebeian. What they fail to remind you is that every book worth reading has a plot, that you can't write a story that's not about something. There's an entire section of academia devoted to pretending that Ulysses has no plot, when in fact it has a very intricate and well-thought-out plot. (Academics are afraid that if ordinary people read the books they like, they will seem less clever. Academics have very low self-esteem, and compensate by making everyone else feel stupid.)
But even if I had put a plot in my first book, I probably would have got lost in the second half of Act 2. That's where I always get lost. That's where my first screenplay starts to sag, for instance. That's also where my current screenplay is stuck.
Although this book isn't a screenplay, I am trying to structure its plot along the lines I learned from screenplay writing. This is not just to make it more commercial. The "gimmick" of this book is the in-depth treatment of Mexican food. If I didn't have a clear idea of where the story was going, it could wind up being a long-winded cookbook instead of a work of fiction. Again I learned this the hard way from my first book, which ended up being a long-winded travel guide.
The three-act structure is older than Aristotle, and works like this:
Act I: we see the hero in her/his normal life, when something happens. The hero reacts to or makes a choice about that something, which locks her/him into the story.
Act II: the hero encounters setback after setback. At first s/he is usually defeated by these setbacks.
In the very middle of the story, there will be an opportunity to give up or escape without finishing the quest, like when the Goonies have a chance to ride up Troy's bucket, or when Sarah eats the forgetting fruit in The Labyrinth.
The story cannot continue unless the hero chooses to finish the quest. That's where the seconds half of Act II begins.
This consists of more setbacks, but this time the hero starts winning sometimes. Unfortunately this causes the antagonist to up their game as well, and the action reaches a peak.
Act III: everyone gets ready for the final showdown. It is the hero's greatest and most difficult test and, depending on what genre of story it is, s/he will either succeed or fail in the end.
Where I got lost is in the portion of Act II after the midpoint. With a plot as long as a novel's, it's easy to forget at this point what your story is actually about at this point. By now at least one major subplot will have come into play, which is good in that it can keep the reader from getting too bored by the main story, but I find I get easily distracted by it and start writing a completely different book.
My initial plan for the pre-writing was to do the summary, then the eight sequences and five plot points, and then the chapter outline. I wrote up to where Esteban's wife leaves him, and then predictably got stuck. Do I make this part of the story about how he gets his wife back, or should I stick with the food? And if so, should I ditch the wife leaving him bit altogether?
So I interrupted the plot summary and started working out the eight sequences early. When I got to sequence 6, I realized one of the reasons I was stuck is that I didn't actually have an Act III. This is unusual for me, as I usually see the ending of a story more clearly than the middle.
One thing about writing: never begin if you don't know the end. It's like chess: you need to see checkmate before you can make your first move. Even if you original checkmate changes, you always need to have one in mind, or you'll never know where you're meant to be going.
I did come up with a third act and, more importantly, a final image with which to leave the reader. This completed the right sequences, and I thought I'd move on to the five plot points before returning to the summary.
Then a new challenge emerged: the third act twist. Did I have one?
A third act twist is something that alters or changes the hero's goal, showing they've learned some valuable lesson and are different then they were at the start of the story. Some twists are earth-shattering. Luke Skywalker goes to Bespin to rescue his friends and kill Darth Vader. Then he finds out Vader is his father, and that goal goes out the window. Or take the kids in Stand By Me, who set out to achieve fame by discovering a dead body, but after their altercation with Ace and his gang, they decide to make an anonymous call, taking no credit for their deeds.
So what's my twist? Well, Esteban's first forays into cooking are all about uncompromising authenticity, and motivated by the death of his mother, who cooked delicious but rustic Oaxacan food. After coming to grips with her death, he finds his own identity as a chef and is able to re-invent Mexican food as haute cuisine. His food becomes an expression of himself and his pride in his heritage (which is why his restaurant is called "Patria"), and that's what earns him the Michelin star.
Anyway, that's how I spent my week. Writing is harder than it looks.