There's always at least one listener...

...who, according to a former broadcasting school instructor, knows more about the radio station where you work than (s)he should.  This listener, for instance, will request a song.  If you say, "I'm sorry; it doesn't look like we have that song here," (s)he'll respond, "What?  But it's cart number 317!"  You'll think to yourself, "This listener doesn't work here.  This listener has never worked here.  We don't announce cartridge numbers on the air, post them online, or mention them to listeners on the phone.  How on Earth would a listener know that?"  I remember when one of our most frequent listeners called KCOU and requested a song I hadn't played before.  It sounded vaguely familiar, but I was pretty sure we didn't have it on vinyl or CD.  I took a chance and asked the caller, who didn't work for the station, "Is it on cart here?"  "Yep," came the reply.  "It's on cart."  Sure enough...