Taken from an old away message and from someone's site:
You might be a Renthead if . . .
~You've "stalked" a cast member
~You know all the words to La Vie Boheme.
e.c. if you understand all the references in La Vie Boheme.
~Your friends say you're "addicted" or "obsessed".
~You've dreamed of playing a part in Rent (even if you can't sing or act).
~You can recite/sing the lines along with your favorite character.
e.c. you can without your favorite character.
~You walk to the beat of Rent songs.
~You find yourself explaining Rent to anyone around you (perfect strangers count) at any given moment.
~You can't sleep at night because the entire musical won't stop playing in your head.
~You have "No day but today" written everywhere
More reasons you are a RENThead
hmm...