On my first playthrough of the game, when I arrived at the Sensate place and wandered into the sleeping room area, the clerk told me that "I" (a previous incarnation of TNO) was a Sensate and had a room reserved since a long time ago.

But, on my second run through the game, the clerk doesn't recognize that TNO is already a Sensate. What's the factor in the clerk recognizing TNO as a Sensate from one of his previous incarnations, and giving you his room key?

I discovered that it's from completing Nemelle & Aelwyn's quest.