Books and tools are my two vices as well.<p>Books especially -- there&#x27;s something to be said for the user-interface both of an individual paper book, and of a whole bookshelf, in terms of ease of navigation. PDFs allow you to grep but spatial memory is much better suited to physical things. And I&#x27;m much more likely to pick up a paperback from my bookshelf when I&#x27;m looking for something to read than I am to go find a PDF and sit in front of my laptop&#x2F;tablet.<p>And finally I really like the social aspect of physical books. &quot;Hey, we were just talking about X, and you might like this book!&quot; works way better with paper than with a PDF.