Dollhouse, Season 1

DeWitt:
In their resting state, our actives are as innocent and vulnerable as children. We call it the "Tabula Rasa". The blank slate. Now imagine the imprint process filling it, creating a new personality. A friend, a lover, a confidant in a sea of enemies. Your heart's desire made flesh. And when the engagement has been completed, all memory of you and your time together will be wiped clean.