In general, I agree, but this is not always true. Some non-fiction books read very much like fiction. An example that I recently finished is Endurance by Alfred Lansing, which tells the story of Ernest Shackleton's failed mission to cross Antarctica on foot in 1914 (they got stuck in the ice only a few miles from land and spent the next year and a half stuck drifting on the ice before making an escape attempt when they finally reached open water).

Lansing spent years doing research for this book, including interviewing all the living crew members, and it is 100% true. But it has a proper plotline, fantastic character development, and a very climactic and happy ending. Reading ahead won't exactly ruin the story (the basic points of the mission are commonly known anyway), but there's no advantage to doing so.

In other words, some non-fiction books are novels too, and they should be read like novels.

Your example is technically not fiction, but as you point out, its main purpose is to enthrall the reader with a compelling story, not to convey a large amount of dense information in the way that textbooks, manuals, and academic papers do.

If a reader wanted to extract and retain as much information as possible from Endurance (say, if they were studying it in school, or read it but found they didn't retain a lot of the key points), they would still benefit from skimming, skipping around, taking notes, and other advice provided in this post. This advice applies to anyone who wishes to extract and retain information and understanding from any given piece of text, fiction or non. Just don't spoil compelling stories for yourself unless you really want to.

Oh ok! I skip through long-winded details in the novels all the time, hence the confusion. Thanks for the clarification!