> If you want to write a book, then write a book. Don't make a movie if what you want is a book.

It depends a lot on the book/plot/style. If your book is about self-introspection, for sure it's going to be difficult to make a movie out of it. But there are many books out there which can be translated reasonably well into movies. An extreme example, but the Odyssey from Homer antiquity had absolutely no comments on how the characters felt and all, and merely describes a series of adventures.