I was shocked at all the annoying things about a paper book that I had never noticed before.

Same. Paper books are terrible. Can’t change font sizes or font type. Much heavier than my Kobo and often, my iPad. Books have an atrocious UI for their one task of reading. Ungainly, close of their own accord, often the wrong shape or size for my hands, often smell bad, and take up huge space. People just like them as that’s what they are accustomed to even though they are mostly a failure at what they are intended for.

How did people read paper books? How did I? Their only advantages are that they are (sort of) disposable and have no DRM.