I resemble that remark, particularly with regard to antique programming books I'm not yet willing to discard. The top of one of my many bookshelves has stacks of computer books I never expect to use again - but kept. I did get rid of a handful. But why do I need most of a multi-volume series on the X-Window system? I *did* get rid of a few when I moved them out of the east-to-reach shelves, but only a few.