I just came home from a trip to our neighborhood branch of the city public library -- I had a book on hold to pick up, and I took some time and browsed around and walked out with an armful of fiction and light nonfiction.
I love, love, love that feeling of walking out from the library with anticipation for what's in those books. Even though I probably won't love or even finish all of them -- that in itself is one of the happy things about the library, that freedom from any sense of obligation -- I always feel optimistic and excited after checking books out. This is even true at the university library with research-related materials -- I don't think that the library happiness is different with different libraries, even though my reading experience and attitude certainly is for research vs free reading.
As I'm thinking about this, I realize that I don't have any unhappy memories or thoughts associated with libraries -- with any of the several libraries I know well. And I have so many happy ones. Reading has, over the years, sometimes gotten complicated, since it's what I do for work as well as play. But exploring, gathering, skimming in the library is unadulterated pleasure.