I think I’m somewhere in between. On the one hand I treasure my books; I do my best to treat them decently. I own far too many of them, part with them a bit too reluctantly, and I think a book signed by the author is a lovely thing. I wish paperbacks were produced in a more durable manner, and I prefer the durability of hardbacks, for all that cost, space, and the logistics of dragging hardcovers around often keep my from purchasing them.
On the other hand, I tend to be hard on objects. If I’m engaged with a book, it gets dragged around, inadvertently damaged by splashes and spills, inadvertently battered by being dragged about in various bags. And too, while I rarely write in books, I agree with lnhammer that other people’s marginalia are fascinating, especially after a few decades have passed.
I try to avoid cracking the spines of my books. I’m mildly irritated if someone else does crack the spines of my books — but not at all troubled if they crack the spines of their own.
I treasure my battered childhood books, because I treasure the memory of the child I was, and I know that she was even harder on her books because she cared about them so intensely. Those books are old friends; when they finally fall apart, I hesitate before trading them in for new editions.
The first time I met a child reading Ghost Horse, and saw the folded-down pages, the bent and battered cover, I felt incredibly honored, that anyone would put that much energy into something I’d written.
So I think my take probably falls somewhere around: treat your books well if you can. Never consciously damage them. But if they take on some wear and tear as a result of your relationship with them, don’t sweat it, either.