Is it what you know that makes you a librarian? Or is it how you behave?
If you think it's the former, then take the "Are You a Librarian" test. If you think it's the latter, check out "You know you're a librarian when..."
The latter I believe is a better "test" because I smiled a lot. And if you don't understand what I mean by that, I suggest you check out the second link.
Category: Librarians
