They don’t literally forget who they are, since their actual beliefs and desires remain the same. (Put in terms of the model: their Belief and Desire boxes retain their original contents.) However, fully immersed actors ‘forget themselves’ in the sense that they actively ignore facts about who they are, temporarily subordinating their own thoughts and feelings to those of their character. Actors forget their identities like stoners forget the quadratic formula. The information isn’t gone – just temporarily offline. – Aeon