Rebecca's case

Incidentally, I've moved to another country. But let's get to business.

"The Man Who Mistook his Wife for a Hat" might be Oliver Sacks' best known book, and consists of case histories. In one of them, Sacks tells about a 19 year old Rebecca who is mentally deficient (and unable to read) but loves stories. "With Rebecca [..] the emotional and narrative and symbolic powers can develop strongly and exuberantly [..] while the paradigmatic and conceptual powers [..] are only capable of a very limited development". Rebecca enrolls in a special theater group. "And now if one sees Rebecca on the stage [..] one would never even guess that she was mentally defective."

This is a moving tale of a young woman exceeding her limitations, but there's more. The roles that Rebecca adopts convincingly on the stage (I'd like to hear a real example) are probably people far more intelligent or "conceptual" than her (after all, she cannot read). Let's say, daringly, that they are fictional identities. Adopting such an identity allows us to do something we could not otherwise do. Maybe everyone needs a narrative. A high school student may say that the role models and ideals given by the media are stereotypical and restrictive (as they are), and that "we should live without such artificial constructs". But of course it's possible that we could not do anything without them. Did Barthes say so? Or Foucault (but he was too obsessed with his "discourse")? Or maybe Berger & Luckmann in "The Social Construction of Reality"..