When writing a novel, there is a place where you brain is going “Only 20 pages? Are you nuts? You have to write 40 times that to finish the book!”

I also run into that when researching the places and times for the next novel.  Pick up a source you think will be great, read 80 or 90 pages before you realize the author is only interested in relaying nominally interesting anecdotes about high-level goings on, with none of the detail of daily life I’m looking for.  So I’ll put that aside, grumbling about the lost time, and pick up another.