Much of the time, which is why I highlighted search. But especially for technical books, being able to put your finger in one place and flip back to where you are and glance back at where you are holding your finger is a physical metaphor that does not translate. Similarly for maps or lists.

"Wait, didn't that character die in the last chapter" is easily solved by flipping back a couple of chapters. If you search for the right thing you can find it too, but it's relatively painful for quick checks.