This may sound weird, but I actually love staring at my bookshelf. I often will go, pick up a book I haven't thought about in a while, and read it again. I've filled it with (mostly) timeless technical manuals, plate picture books (like pictures of the cosmos, airplanes and things like that), plenty of sci-fi, flight instruction manuals, foreign language dictionaries and other odds and ends. There are plenty of books which I'll buy on Amazon and leave on the shelf for a couple of years and I'll randomly pick one up and start reading.
I think the point here is that a bookshelf makes ideas have a geographic location. With web sites, knowledge doesn't occupy physical space and doesn't have the same permanence which a book occupies. With the bookshelf you're reminded of ideas not because they're hyperlinked together in some ever shifting zeitgeist, but because they're literally sitting right in front of you.
The (method of loci / memory palace) technique of associating information with spatial location has been used for hundreds of years and is still used today in competitions.
Latency of recall affects recombination/creativity. Same reason why native apps have a perceived UX advantage over web-based apps, even milliseconds can make a difference. Typing search terms or paging through book covers is not the same.
A couple years ago I had the idea to create some kind of projection system that would beam images of my e-books onto a wall. I'm not a hardware guy and am not sure there would be a market for it, so I didn't pursue it, but I hope someone else does.
I think the point here is that a bookshelf makes ideas have a geographic location. With web sites, knowledge doesn't occupy physical space and doesn't have the same permanence which a book occupies. With the bookshelf you're reminded of ideas not because they're hyperlinked together in some ever shifting zeitgeist, but because they're literally sitting right in front of you.