I'd bet you're not crazy. My hubby doesn't smoke in the house and for days I was bugged by an odor of smoke in the house. Turns out hubby was smoking as usual in the screen porch and the fickle breeze was carrying it into the house through the a/c.
And it DID drive me nuts til I figured it out, because OF COURSE I was the only one who smelled it.
Anyhow-- I can smell the difference between cig smoke, wood smoke (or brush fire), and house fire (plastic-y with wood smoke), and electrical (extremely plastic-y), and even if my car's engine is too hot and therefore low on oil.
But now I have a question: someone told me once that the nose "turns off" when we're asleep. This supposedly was from a fire prevention person, and that was supposedly the reason why people sleep through fires.
I've never heard of such a thing; has anyone else?? Mario?? any takers??