Absolutely. The few authors that I love the best are streets ahead of the rest. Reading other authors is for me really just a search for the Next Big Thing. As time marches on, re-reading old favourites rises in value relative to reading new stuff, on average.

>Though our eyes may pass over all of the words and our hands may flip through all of the pages, what we read is never the entire book

The idea that reading is encompassed by the eyes zig-zagging down the page like a raster scan is an example of the 'bucket theory' of the mind, as Karl Popper put it. This is where knowledge supposedly pours into the brain passively via the senses. Which is a fallacy.

>If I read for pure pleasure, what harm is there in forgetting?

This is also the reason I've never seriously tried to speed read. Perhaps I'm mistaken about this, but why wolf down an expensive meal? There's nothing to be lost from optimising pleasure since it derives from the meaning i.e. from the true content.

>When we read, certain notable phrases, concepts and ideas [...] stand out more clearly from the others.

Oh yes. This is the Searchlight Theory of the mind, where our attention is continually homing onto the most interesting or semantically useful bit of whatever we are doing.