Language of Self-Destruction

I saw a guy recently become invalidated by his own words. This guy has a habit of saying things he later can't remember saying. It is denial for convenience and raises the question of whether there is any value ever to saying things we may later feel the need to deny. In the case of my friend, nothing he says comes without the question of it being cancelled later.

Shakey credibility is a corrosive agent.

So is it possible to present one's self in a manner that undermines one's own presence; the function of a communication to create a hollowed out shell of meaning?

Conversely then, can language make us actual?