So, I was talking about trials and writing. More specifically: I gave the example of a trial prosecutor questioning an eyewitness in a homicide case, and having to react spontaneously when the witness wanted to go beyond pretrial prep to give a fuller account of everything she saw. My account included her putting herself on the courtroom floor, in the fetal position, to best represent her real life experience.
So what does any of this have to do with the art of writing? Just this. Prosecutors try to plan out every development in a trial, just as many fiction writers are inclined to map out in advance every scene in their book, even every moment within every scene. In my humble opinion, a fiction writer sometimes reaches a point where a main character decides to take off on their own — if you've created a full-bodied character in the fictional present when the book begins, that actually SHOULD happen. And when it does, you just have to follow the lead of that main character, even if the plot goes off on a different course in the process.
Sometimes your main character will need to get out of a chair and put themselves in a fetal position on the floor. And you just have to respect that and go with it.