I don't understand how people, other than those with perfect memories, can be satisfied only reading a book one time. Any book that I thought worthwhile enough to finish the first time, is at least worth picking up again to see if I still think the same way. Even if I don't find it as useful the second time through, I recognize the perspective I've gained.
Well, a novel is less likely to be rereadable than, say, _ANSI Common Lisp_, because you'd use the latter as a reference. I sometimes reread novels, but only the really especially good ones, if I remember that I've read it before. In general, I don't read novels for perspective, though it's really nice when there's some to be gained, rare though that is.
I've probably read somewhere around 10K books, the vast majority of which were novels, and way more than half of which were not really worth reading had my time been as limited as it later became. When I was a teen, it was easy to finish two or three books a day of stuff I'd throw against the wall by chapter two, now. The fact that I've read it and finished it is no indicator of worth. :)
Anyway, I used to own a coupla thousand books, but after moving several times without having looked inside most of them, it dawned on me that carrying around all this dead tree was not very useful.
I think the main difference between us then, is that I don't have a great interest in reading lots and lots of books. I generally don't have the patience to finish a book once, unless it's a book that I'd read several times. I wind up reading far fewer books than yourself.
So for me, the comments I made apply to novels as well as reference material. Second reads give me another chance to observe things like structure, or enjoy knowing what's going to happen.
Actually though, the biggest factor for me was recognition of my own mortality. When I was a kid, I'd keep books and reread them 5 times. When I was a teenager, I'd reread them twice, and keep them expecting to read them more. Now, I realize there's a limit to how much reading I'll be able to fit into the rest of my life.
