I don't know where the characters are going to go or what's going to happen. I know that something inevitable will happen. I know that they want certain things and they're in a certain room and they smell like this and they look like that. More often than not, an entropy creeps in that strangles me, and then the inevitable happens. I don't know if I have the ability to write an ending like My Fair Lady's, when everyone gets what they want after a few minor conflicts. If I tried to write that it would just be false. Or I'd have someone enter with a machine gun.
Sometimes, even when I'm writing the lyrics, I'm not sure what I'm getting at, but then months will pass and I'll listen to it and I'll understand it completely. I think I trust myself in that most of what comes out of me will be honest. Even if it seems like it doesn't make a lot of sense, I realize that it does. It's hard to follow, and maybe there's a lot of subtext to it that nobody knows, so it makes it impossible to follow.
So that's why one of my rules of parody writing is that it's gotta be funny regardless of whether you know the source material. It has to work on its own merit.
Experience of life (not of books) is the only capital usable in such a book as you have attempted; one can make no judicious use of this capital while it is new.
The best way is always to stop when you are going good and when you know what will happen next. If you do that every day when you are writing a novel you will never be stuck. That is the most valuable thing I can tell you so try to remember it.