So, gleefully realizing the futility suggested above, my cynicism jumps into the fray and asks "what mystery?" This is, in fact, a very spiritual perspective, at least for a Buddhist. Buddhism presumes that in life we are dealt both joy and suffering and if we are consistently mindful of accepting this immutable truth, we can find a measure of peace. So what's the big mystery? What is, is.
Of course when our ego is involved we create judgments: If life is good we are doing something right; if life is bad, something bad is being done to us, and the mystery is how to make it stop. So we search for something we don't think we have to mitigate our discomfort. But if we eliminate the judgments, then life becomes what it is-whatever it is. Or to put it somewhat more bluntly: life is what we are given--deal with it.
Now this is not to say that we don't, by the choices we make, create some unhappiness for ourselves, or to imply that we have no control over changing some things that cause us discomfort. But perhaps the mystery arises in why we think that we will figure out a way to rid ourselves of all discomfort for all time, if only we can figure out the "right path."
But in the end, I have to wonder why it is so hard for us to accept that in spite of whatever is happening in our lives, we are okay; because life is what it is, and there is no better place to be. There's not much mystery in that.
So perhaps the biggest mystery is why we find it so hard to accept that there is no real mystery.