How to know you've been spending too much time in the mystery section.

Last night I had a dream in which I wore a dress with this image on it:

 
It was slightly different -- no text and the colors were inverted (crazypants background, with a black gun image), and the gun was on one side, pointing down, like an off center stripe -- but I woke up and immediately knew where I'd seen it before. 

Weird.  I haven't even read it.  And I can't imagine a single situation in which I would wear a dress with a big gun on it.