When my husband and I moved into our current apartment, the only pieces of furniture we had were a bed and a kitchen table and chairs. The first item of furniture we had to purchase was bookshelves. As we unpacked all of our books, particularly some older ones that had gotten a bit musty, I bemoaned the fact that e-books weren't yet widespread when we were in college/master's programs and thus we accrued pounds and pounds of books to move over and over again.
In reality, we could probably give most of these books away. But every time I try to sort through them, I end up spending hours flipping through my favorites, re-reading passages, or thinking that eventually I'll return to studying such and such a language, so I'll need to keep the dictionary for it*
Recently, re-reading has been on my mind. When I was younger, I read nearly everything twice, and my favorite books probably twenty times or more. Now, unless something is important academically, or one of my favorite childhood novels (Sally Watson), I rarely re-read anything. In fact, I feel overwhelmed by all the things I haven't read, both academically and in terms of my other interests. There's no time to re-read, when there's not enough time to first-read! But then how do I remember things if I don't re-read? What about things I enjoy reading? Sometimes they're even better the second, or fourth, or tenth time.
Books are also far more readily available than they were in my childhood. I can get a new book in seconds on my Kindle, rather than waiting for interlibrary loan from Big City Library or begging my parents to drive me an hour to Shopping City, the location of the closest bookstore. In turn, this means that when I want to read something enjoyable, there's no need to re-read old books as I have easy access to new ones.
I would never trade the access I have now for re-reading my favorites, but sometimes I do miss the feeling of having read a book so often I practically have it memorized.
*Even though I really just use Google targama for everything :-)