There was this bookstore down the street from where I lived. Really it specialized in antiquarian books, and really it was something for the old lady whose family used to own the mill when there was a mill to do. I don't think any of the very impressive and very expensive old books ever left their display cases, and I doubt she expected them too, East Bumfuc, The South not having an abundance of bibliophiles and all. I started going there for the comics when I was around 10, and eventually she started just handing me books along with them. Lovecraft, Dunsany, Robert Anton Wilson, Martin Gardiner, old math books she picked up when buying out library and estate sales. She had a box of old Shadow pulps waiting for me one day, because I'd talked about Houdini once and she remembered Walter Gibson had ghost written most of his books. She'd charge me for the comics, but not the books she gave me. She did the same for everyone I knew who came in regularly; not horror, weirdos and math, but stuff they'd be into. I didn't think to ask her why until I was a teenager; "I think you'll give them a good home" was the best answer I could get out of her. On reflection, I have her to thank for a lot of my obsessions. She moved away to be closer to her grandchildren when I was in the 10th grade. She left a sign on the door explaining that and saying something along the lines of "the rent is paid until the end of the month, I left the door unlocked, help yourselves!"
I think all bookstore owners are eccentrics, though maybe not as much as her. My local used bookstore now is run by an old guy who used to be active in radical politics, won't talk about how, but he knew Bill Ayers, Abbie Hoffman and William S Burroughs and gets really, really angry when he talks about J. Edgar Hoover for reasons he likewise won't talk about, his daughter, who I've never heard speak but is a hugger, and a small army of cats.