Any ideas on how to solve the mental map-making problem? I've been reading on my computer for a long time. Sometimes the problem shows up, sometimes it doesn't

Any ideas on how to solve the mental map-making problem? I've been reading on my computer for a long time. Sometimes the problem shows up, sometimes it doesn't & I still can't tell why. "1. It’s bad for research. I’m working on a book right now and I wanted to use the Kindle for all of my research. Sadly, this is almost impossible. The book is a physical object - you can move through it, skimming for notes and important points - and there is something in our education that gives us a sense of space inside a book. I don’t quite know how to explain it, but you know how you can pick up a book and show someone what you’re looking for in a few page turns? You know it was halfway through, maybe a third of the way down the page, and it was near another set of words. The Kindle is not conducive to that kind of mental map-making… yet."