I have been an existentialist for many, many years.
When we are honest with ourselves, contemplating our existence, we find oursleves isolated, alone with the uncertainty and apparent lack of meaning. But it is not neccessarily true that there is no meaning, it is that everything is overshadowed by uncertainty, doubt.
So we look out into the darkness, the abyss, aware of only our own awareness, alone. This is the human condition.
So what then shall we do?
Some might say that in the context of this uncertainty, and perhaps only in the context of this uncertainty, true freedom arises. ex
Through this commitment your authentic self expresses and creates meaning. Meaning does not exist outside of you, it exists within you, through the ex
There is also the issue of Epistemology (knowing). Through science or other empirical methods, through our senses, perceptions, by mathematical equations, by the study of language, history, etc.
But what about knowing through "direct experience"? An awareness, insight, not describable by words, not transferable from one to another. Beyond the comprehension of our ordinary awareness.