When we attempt to understand our self we must use language. When we identify ourself in language, we lose ourself in language and become an object. The self is undefinable then, and unreachable. When we attempt to represent ourself, then, we forever lose the chance to really understand and know our self. Language is our source of the self and our barrier from understanding and reaching it.
Language is unstable and therefore the self is constitutionally unstable, as well.