To me the realization constitutes in an action of the will, which involves a method, and this is intellectual in nature, or at least partially intellectual.
Recognizing that each of us is living an act is a recognition which results from a process. Even "letting go" is a conscious act of will. This is what Sartre had in mind when he said that we are condemned to be free.
That this act becomes synonymous with what people deem themselves to really be leads is in itself a realization, and the realization that this is so by a particular individual for the same individual is a realization which can be reached as per above.
Now my second point is related to this. I can agree that I am playing out an act, and my realization of this will still have me play out an act (I will be playing it out authentically - here the philosophy becomes more complex as issues of will come into play), and some acts are better than others. That is why I think mere realization is not enough; it is admittedly a seperate issue, but my point is that living the authentic life is not enough, one could live an authentic life (i.e. realize, however this happens) and *then* wish for another, that is one realizes that it is an act, and then also realize that there are better acts to play.
