I once visited...Anthony Powell, who actually wrote a novel called Books Do Furnish a Room. Indeed, they did so in his case. He lived deep in the English countryside, in Somerset, in an old stone manor on many green acres. We had tea in his sitting room, which had floor-to-ceiling shelves on every wall. There were first editions by his good friend Evelyn Waugh, and countless volumes culled from his decades as a reviewer. "I can't give a book up, if it's a book that meant something to me," he said. "I always imagine I'll go back to it one day. I rarely do, but the intention is there, and I get a warm feeling among my books." I wished I could have spent days wandering in that house, as he had books in nearly every room.
From an article by Jay Parini entitled: Other People's Books.
I have given up a number of books that I thought I never would, because I was sure I'd read them one day, but I understand Powell's feeling. Having read a book you have a link with it that won't go away - even the awful books that you know were badly written and which you only read because you had to review them or because someone else thought they were wonderful. And so you keep them, thinking that one day you'll need to look something up in them, or check the title, or make a note to read something else by the same author.
I have a great deal of trouble not buying copies of many of the books I borrow from the library. Having established the link with them, I want them to stay close at hand, not be on the shelves at the library where someone else might take them out just when I need them.