You know you're a librarian when... #3

...you refer to a non-librarian as a "civilian".

You know you're a librarian when... #2

...an online dating site asks for six things you could never do without, and one of your answers is interlibrary loan.

You know you're a librarian when... #1

... you write, in all seriousness, "New books are kept separate from the general population...".