Read this insightful article: https://www.washingtonpost.com/news/the-switch/wp/2016/05/09/researcher-say-computer-screens-change-how-you-think-about-what-you-read/
I decided long ago that I do not like e-books. I prefer to hold a book in my hands. Instinctively, I knew there was a difference. This article confirms that there is a difference, but it doesn't/can't yet explain just what that difference is.