In this instance I'm using the concept of a muse as the source of an artist's inspiration. Using google's "define" (type 'define: word into a search) feature will get more colloquial definitions, which is good because dictionaries only add words after they come into general use. Also, I personally like using
Webster'sdictionary search better. In our use the word muse is a noun, and the third entry for muse on Webster's lists this as a definition: "2 : a source of inspiration; especially : a guiding genius"

So my picture is personifying my source of inspiration as the little angel/goddess, kinda like the good shoulder angel, bad shoulder angel. (like my avatar...)
So... the fickle little tart likes to run off at the most inconvenient times and take her inspiration with her and leave us artists in the dust. I suppose her
absence can be it's own kind of inspiration.... I feel much inspired to draw her in various states of bodily harm....
/EDIT - Hey LS3!! I didn't know you were on the East Coast, me too! (can't sleep....

) ditto on the pain in the ass part.... once I've gotten a picture in my head it usually won't leave me alone until I draw it, but once I don't have any pictures nagging for illustration it's like I'm a blank slate! argh......