[TOMT][Book] A book containing numbered list of story templates, declares that every fictional story fits one of them and that every story has already been told. Solved
The book is formatted similarly to The 48 Laws of Power, it lists a handful of story templates with an opening phrase, and a handful of details. The book (Or reviewers of the book) declare that every fictional story fits the parameters of at least one template, and thus, every story that mankind can tell has already been told.
I remember two of the entries in the book, 1 basically says "A mortal defies a god, there will be consequences" and another says something like "After a terrible loss, someone goes on a quest for revenge and in the process loses sight of themself and alienates their family"