Once you start writing a book, you lock yourself into its world for a year. Or maybe even longer. So be careful when you pick what to write about.
I have locked myself into a book at the moment which I’m tired of writing because of its subject matter. I have personally moved away from it already, but I’m not a quitter and I will finish this book, although it’s painful and makes me want to gag sometimes. I hope I’ll learn my lesson and be more careful in the future.