is important. It drags the reader in (supposedly). If the first sentence succeeds, the book will succeed (supposedly). I agreee with these ideas (a little bit). But I might express them a little differently, like this:
The first sentence acts as a signal to the reader about the book to come. If audacious, the book to follow will be audacious. If complex and lengthy, the book to follow will be thus. I don’t actually believe this, it’s just an example of the type of thing I do believe.
I’ve spent a lot of time reading first sentences and I do believe they affect people’s tendency to read further. But this doesn’t mean they have to be fantastic, incredible sentences. They can start slowly and simply, meaning almost nothing on their own. If they do not offend, and set up a single idea, that is enough—even if that idea is not the central idea of the book.
You can build from within, from underneath, build a rhythm. This opposes the idea of a top-down sentence: a structural first sentence. This opposes the first sentences of Dickens or Tartt, but I like the options it presents.