I once heard a distinguished professor answer that question with "I have read at least half of them at least two-thirds of the way through." On the other hand,

I once heard a distinguished professor answer that question with "I have read at least half of them at least two-thirds of the way through." On the other hand, he had books that were nearly falling apart from re-reading. Eco on libraries reminds me of a piece by Michael "Rands" Lopp from 2006: "The cliche about hardware stores and people over thirty is this: it’s a toy store. We go there to buy crap that looks cool, but that we don’t really need. Wrong. My Dad was not wandering Orchard Supply looking for crap; my Dad was looking for ideas. That’s what a great tool does: it inspires you to build." (http://randsinrepose.com/forums/ http://randsinrepose.com/forums/)