Having it all.
I like having books on my shelves. They're my books, and I readily admit that they have value to me over and above the value that they hold simply as books. Most of them carry sentimental value, and many have notes in the margins that make that particular copy of a book important to me. What's more, I simply don't like the idea of walls not having books on them.
Even so, it seems to me that availability is the main issue here. If I had easy and free access to any book that I might want at any time that I might want it, the need to possess the books themselves, would be called into question. And considering that there are always more books that I might want than I can ever afford, at some point along the line I'm going to have to settle for access over possession. And that's true even if I only want to keep digital copies of them.

Now there's a comic that brings back memories.
Go to: Pick a record, any record, or
Go to: Hearing, perhaps, but listening?, or
Go to: The Complete Works.