Humankind has, from the earliest glimmerings of sentience on, endeavored to answer certain questions. What time is dinner? What's for dinner? Who caught dinner?
Once these questions were being answered satisfactorily and moderately regularly for at least a fraction of the proto-human population, we can only imagine that in that warm lull that follows a full belly around a fire beneath the stars, questioning thoughts turned to less important, but nevertheless intriguing, issues. I wonder what those little bitty lights are up there? I wonder how the fire comes out of chunks of cold rock or rubbing sticks? I wonder if I'll get dinner tomorrow, or turn out to be dinner for something else?
Eventually, humankind developed rudimentary societies, and for the first time at least the ruling class of those societies experienced the luxury of not having enough to do. Others in those societies didn't have that luxury but wanted to. Together they conspired to extend these questions still further, so that they could spend their overabundance of leisure time working hard trying to answer questions that had little to do, at first glance, with dinner.
Their experiment was wildly successful. It turned out that even the hardest of workers had an early form of ``attention deficit disorder''. We can speculate that their ready distractibility was an evolutionary advantage - it didn't do to become totally preoccupied with watching your prey in a world filled with other predators, or so engaged with your work at hand that you missed an opportunity for an easy meal. Also, even the hardest of workers in the hardest of times had some leisure, if only in that lull right after a big meal or when they were asleep.
It is only natural that right in the middle of a big hunt or while nursing a child or plowing a field, humans would suddenly stop, somewhat dazed, and wonder things like: Who am I? Why am I here? What is all this? Of course they had no time to think of answers to all of this, so the appearance of professionals that would try to answer them for them in exchange for food was a welcome relief.
The most profound of these is also the most unanswerable: Why Is There Being? (Also known as why are we here, where did all this come from, why is God there (if you believe in God and consider It the answer), why is Physics there (if you believe in Physics and consider It the answer).
This question has an infinity of possible answers, and over time we've cranked away at generating a tiny fraction of them for active consideration.
However, the task is fairly obviously doomed. In absolute terms the question cannot be answered. This is not because of the usual reason - that if we give any sort of an answer, the question can be repeated for the answer (ok, so the Universe is here because of the laws of physics, the laws of physics are there because of God, God is there because...).
The task is doomed at a prior stage in the cognitive reasoning process. It is doomed at the epistemological stage, by the nature of the word ``why'' (or its many counterparts, where, what, who). It is natural for us to use these words as they have meaning and relevance in our daily lives. We feel like all questions should have answers, and when we look at them closely we find that certain questions, of certain kinds, don't. Here is one:
Why should all questions (including this one) have answers?
This is the kind of obnoxious question that parents eventually learn to answer (like all the rest of the related questions and question chains) with the simple word ``because...''.
Which is, as any small child rapidly learns, code for ``this question cannot be answered''. ``Because'' as an answer to a ``big'' question often means that it isn't a question at all. At least, not one that we can answer in the same way that we can give somebody the time upon request.
Such a ``question'' calls into question (sorry) the foundation of what we know, what it means to ask questions at all, and how we should cognitively interpret the answers (such as they are, if they exist). All of which leads us, by a roundabout way, to consider the issue of axioms.