I believe the mystery has been solved. At least, I’m pretty sure. I feel fairly silly and damn lucky I didn’t blow my house up.
While in the kitchen the other night, I was getting something out of the freezer and as I shut the door, I caught a whiff of The Smell again. This totally sent me into “Where in the hell is it coming from???” mode and I set off like a bloodhound in my kitchen, vehemently sniffing anything and everything. I must have looked like a total nutjob.
Finally, with my nose practically shoved into the burner, I discovered the culprit. It was the gas on the stove! The stove was turned ever-so-slightly left (even though I could have sworn I checked that like, 30 times) toward the “low” setting. It wasn’t even on the low setting, really. It was about a 1/4 inch off the “off” mark, no where near an actual setting. Yet, I had to bear in mind that the #2 setting on my stove sometimes seems like “high boil” because it’s a new stove and really efficient. It seemed reasonable that the stove was leaking a very small amount of gas that was being diluted by the many fans I have running. It makes perfect sense now that the longer I was away, the stronger the scent would be. It doesn’t quite explain why it happened when I left the windows open, but I’m not going to argue with it. Since I’ve turned the knob a quarter inch back to the “off” position, I’ve not smelled it. That had to be it.
What a maroon.

Good thing you found it – gas leaks are no good! Wonder why you messed it being on? I do that sort of thing too.
duuuuuude.
@GFI: fortunately not that big of a deal. it was SO minor of a leak. I couldn’t smell it until I stuck my face right down an inch from the holes. So don’t worry, I’m not going to blow you out of your apartment any time soon. hee!
@Cheri: yes, totally! I think I must have bumped it the knob and not realized it.
YIKES! Good job locating that, Joelle.
Thank goddess you finally found the smell and were able to turn it off!
Les~
dude, that’s scary but totally get it. we were smelling gas on and off for 3 years. until we did our remodelling and the man’s cousin (who’s a contractor) said “put some soap on it, if it bubbles, you have a leak.”
and leak we did. so we were slowing killing ourselves for 3 years. lovely.
isn’t being an adult grand?
Whew!
I am glad that you found the gas leak; those can be scary. I have a very sensitive sniffer, but the wife is all like “I can’t smell anything,” when I notice an odd odour.
There should be a light or something beside the knob that states whether any gas, of any amount, is escaping. Like an “on” light. I blame the stove.