So, what's the most interesting question you've ever had?

We get students of some ilk or other in periodically with a list of questions about the Mysteries of the Library. 

Where is the card catalog (scratch paper gone long ago).

What do you like about working in the library (the peeps, kiddo).

Can you use the Internet without a library card (sort of yes, sort of no).

Do you have a catalog and databases on separate computers?  (All on everything)

WHAT IS THE MOST INTERESTING QUESTION YOU'VE EVER HAD????????????????????? (So, of the perhaps thousands I've answered over the years, you think I have a favorite?  I do not.  I like every question I get that isn't a math or car repair question.  I love recommending books and authors to avid and returning readers.)