Vanity is...

...waking up at 5 AM wide awake, thinking briefly about going on a run, and then opting not too despite being WIDE awake with no prospects of going back to sleep because you got your hair cut the previous day and knowing it would still look pretty awesome even after sleeping, not wanting to mess it up by sweating, thus having to wash and blow dry it.  Oh the horror! (And that sentence is a monstrosity all on it's own.  Excuse the massive run on sentence, please!)