Postcard: Vellichor

From January 2016 to February 2019!  This came back today, a rainy day midweek, and it was a cheerful thing to see in the mail.  It was handed to me along with a bouquet of red roses for Valentine's Day, though the roses came from my well-loved companion husband and the postcard from a library worker in Coeur d'Alene.

The sender writes:

I had to look up the word "vellichor"--and I work in a library!  Is there a word for "the strange wistfulness of libraries?"

If you didn't know--and I certainly didn't before I tripped over this wondrous old word on the internet--vellichor refers to the strange wistfulness of used books or used bookstores.  It's tempting to think it might also apply to libraries, which also are full of used books.   I find that the feeling in a used bookshop is different than the feeling in a library, even though both are filled with used books. What do you suppose makes the difference?