Wes

Wes used to be James' and Anesh's roommate. Then he moved out. He is remarkable only in how little of an impact he had on their lives.

Knowledge of Wes became relevant when they realized that they had once had a roommate, thus reminding them of the existence of a third room. Knowledge of Wes was not affected by whatever it was that removed their memories of Sarah, as he was too inconsequential.