Weird Things about Writing a Novel

Established authors know there are various weird things about writing a novel. Authorship is more than a lifestyle, it's a mindset. Here's a list of some of the oddities:

1. Third person is still first person. If you think third person writing ("he said" or "she said") is easier than first person ("I said") because you don't need to get inside their head, think again. The narrative structure of a single-viewpoint third person novel is almost identical to a first person novel. The story has to follow one person everywhere, showing only conversations including that person. And the narrative descriptions need to be the "thoughts" of the viewpoint character, even if you can't say "I thought." Even more bizarrely, the vocabulary of the descriptions should match your character's ability, and their perspective on the events needs to be consistent with their character. Might as well change it to "I" is what I recommend.
2. Immersive writing means there's no book, no author, and no reader. Aren't I writing a book? No, you don't exist. This advice applies to "immersive" genres such as thrillers, romance, sci-fi, and other genre fiction, but not so much to deep literary fiction. A truly engaging book should be like sitting on the protagonist's shoulder, seeing what they see, and hearing their thoughts. If done well, the book is immersive and in-the-moment. The reader forgets that they're reading words, forgets that it's a book, and reacts as if they are just mentally in the world with the characters. The way to do it is to learn more about "immersive writing" and "in-the-moment" scenes.
3. Don't be nice to your characters. You want to be awful, torment them, until the very end. Otherwise, there's not enough conflict in the book to keep a reader engaged.
4. Dialogue is fake but not too-fake. Good dialogue is not much like real dialogue, but it seems like it could be. People respond with cute, witty comebacks without any hesitation. There are no umm's, ahh's, and er's. People rarely interrupt, don't ignore each other, always reply, and never talk at cross-purposes. And they never greet each other or say goodbye. Snappy dialogue cuts out all the boring stuff.
5. Everything is fake but not too-fake. And it's not just dialogue. The whole story is a kind of semi-plausible fake world. Research everything that you can about anything that readers could check: historical facts, technologies, foodstuffs, medical conditions, and lots of other stuff. Otherwise some reviewer will go check on some weird issue, and write a critical review. Your whole story has to be sort-of believable, as much as possible, although usually not to the level of a documentary.
6. Even imaginary stuff has to be real. Even where things are totally unrealistic in the normal sense, like dystopian society rules or fantasy magic systems, they must still make logical sense within the context of the alternative world you've built and its rules.
7. Foreshadowing is the dark art of writing non-spoiler spoilers. The aim of foreshadowing is to hint at something hidden, but not in a way that reader's notice. If it's too obvious, then it becomes a "spoiler" and your reader reviews will use the word "predictable" lots of times. But you cannot win this game: some readers will say "predictable" whereas others will say "unexpected twists" about the same book. Just do your best to balance it. Try to make it non-obvious on first read, but very obvious on the second time through. Best of luck.
8. Your best writing is the worst part of your manuscript. There's writer advice that you must "Kill Your Darlings." What this means is that the writing of which you are most proud is probably the part of the story that readers will dislike. You need to check your ego at the door, stop trying to show off with words, and just tell the story as if you don't exist. The solution is to avoid "author intrusion" or "heavy-handed writing" and try to write in the immersive in-the-moment style.
9. Characters starting telling you what they want to say and do. This doesn't happen straight away. Eventually, when you are fully "in" the story yourself, the character's personalities and desires actually start to direct you. Non-authors don't believe this happens.
10. You can "fix it in post." This is a movie editing joke that everything can be fixed by editing and revision, and it's also true of novels. Almost nothing is unfixable, and revision often takes longer than writing the first draft. Your novel only has 3 problems: the beginning, the middle, and the end.
11. Listen to the manuscript. This is a weird editor's trick. The author's subconscious sometimes admits to bad writing through the manuscript. For example, you might find one of your characters saying to another, "What a bizarre thing to say!" What this means is that the other character just said something that's out-of-character, and that needs correction. You, as the author, just confessed through your fingertips.
12. Post-completion slump. Instead of a wonderful feeling, your emotions after completing a novel are often down. Suddenly, you go from very busy and engaged to having very little to do. This is true after a first draft, while waiting for editor feedback (sitting on your hands), and also true after it's published, while waiting for reviews to trickle in.