I prefer circadian rhythm-challenged.

I'll admit I've practiced terrible sleep hygiene for most of my life. And lately I've completely settled back into my default nocturnal rhythm. This includes sleeping late, sitting at my desk all day, then often exercising at midnight or 1am, which keeps me energized for hours thereafter. Another point of similarity that makes Kat & I such perfect housemates. She's circadian rhythm-challenged too. We enable each other. And we'd make great vampires. Ugly truth is, I'll have to join the hours of the living soon. Early mornings and long days. Bottom line, it'll be quite a shock to my system unless I start transitioning now. *grumble*