We often hear people use such expressions as: "I've woken up to reality", "It all becomes clear" or: "I've seen the light."
It may or may not be real: more often it is something said along the way to an understanding.
"We can't say anything in a definitive, immutable way". But isn't this sentence itself inherently definitive? Well, the question and the sentence it refers to do not share the same frame of meaning or angle of reference, and we had better not ask it.
We often feel we have seen the light: I might for instance get flashes once a month, each term, every year or even daily. However, seen from a chronological angle, we are just talking about what we feel or understand at a given moment. In reality, everything can change with the passing of time. It would seem to be true of a person's love. You tell someone "I will love you forever". In fact this sentence describes what you experienced or understood, and even promised at the time. But time marches on relentlessly, life is so random, and at a different time and in another situation you might deny or play down what you originally said, or completely betray your own words.
I think it is more appropriate to understand enlightenment as a process. We are in an ongoing process of awakening. Awakenings which constantly bring new awareness of our individual life, of our collective existence, of the workplace, of the nation's culture, of the natural universe, of strangers and people we do not usually pay attention to. In general, our awakenings depend on the development of our methodology, our changing perspectives, linguistic changes, the endless shifts of language, exchanges between opposites, the practice of silent observation and so on. Our awakenings take place in a chronological context.