The reason I own physical books and keep them on display in a bookshelf has a simple Proustian answer. Each book is a souvenir with the power to flood my mind with memories of my past. Scanning my eyes across my shelf is akin to death since it causes my life to flash before my eyes. Beholding a book brings me back to the time in my life when I was reading that book. Without my books I may forget my past and special memories, but because I keep them and display them, the history of my life is ever-present on my bookshelf. This is why I could never get rid of any of my books. To lose them would be to lose a part of my soul forever.
I truly feel sorry for ereader users. I don't think it's possible for you to share this experience. The tactile interaction just isn't there to imprint memories with each book you read since there is no physical totem.