When I switched from physical books to a Kindle, I lost my ability to tell where I am in a book. The percentage counter is accurate but it doesn't map to the physical sensation of 'half the book in each hand' that I'd been using for thirty years as a subconscious measure of pacing. The first month I found this maddening.

I adapted. I now read in a way that's less spatially aware and more temporally aware — I track time spent rather than position in object. This is actually more accurate for dense books where chapters vary wildly in length. But I miss the spatial component and I don't think I'll fully stop missing it.

The thing e-readers do better: the dictionary lookup has changed how I read. I used to let unfamiliar words go, building meaning from context. Now I look up everything immediately. My vocabulary has grown noticeably in three years. That's a genuine, unexpected benefit.