To me, they mean possibility.
There are thousands, even millions, of books in libraries in every town. For no additional cost to patrons, books are available for reading. (Just return them on time — a challenge for even the most voracious reader!)
I have read the first two Fever books by Karen Marie Moning at the recommendation of my friend Karen and have been totally sucked into the world of Fae (and the sexy lead male character).
I perused (okay, totally read) The Happiness Project and realized I could be happy living in comfort on the Upper East Side, too — especially if I could write a book about how happy it made me. (I jest. It had some interesting information and ideas in it. Plus, I'd only be happy on the Upper West Side.)
I had only two days to try to (unsuccessfully) finish The Princess of Mars before I had to hand it over so these pesky Jane-come-latelys could discover John Carter. (Thanks, Disney, for your impeccable timing — though, in all fairness, it's as much my own fault putting Edgar Rice Borroughs' The Land that Time Forgot at the top of the stack, thinking it would be better. Ha.) I reserved it again as soon as I returned it, and I should get it (back) by the end of the summer; by then, I'll be ready to re-read Ray Bradbury's introduction.
I'm able to preview books for friends and family, recommend them and share any copies I might own (only because the public library rightfully frowns on subletting books). I have discovered plenty of books I plan to add to my personal library, such as the aforementioned (good) Edgar Rice Burroughs book, and others I'm glad the library invested in for me (The Land that Time Forgot, anyone?).
I've spent plenty of time with Mr. Putter and Tabby, and their good friends Mrs. Teaberry and Zeke.
I've wandered the stacks, looking at the shelves bursting at the seams, wondering how I can find enough time to read it all.
I also have encouraged my local government to support library services. Everyone deserves to consider the possibilities of what these books can offer them: an education, a dream, a plan, a new poem, a new way of thinking, a new recipe, a chance to just think. I love my library (and the librarians inside), and I plan to love it for as long as it stands (which I hope is longer than I do). Love your library, thank your librarian — and remind the people who fund them how very, very important they are.
Ray Bradbury said it best:
I spent three days a week for 10 years educating myself in the public library, and it's better than college. People should educate themselves - you can get a complete education for no money. At the end of 10 years, I had read every book in the library and I'd written a thousand stories.