The concept of one's mortality, although known, is not truly felt until approaching ones own true demise. How we grow so intimate with the concept of time yet unchallenged and its abundance, we fail to see how shallow and swift moving this stream of life truly is.
At first, there is the shock of elders dying. Rather a relative or kindly old mentor from childhood. Perhaps it is a pet or even unexpected and early demise of a friend. Reality is shaken, but somewhat in tack as we rationalize away the thought "that could have been me".
Then, as time goes, more and more leave us and the guilt of being a survivor takes root like some unseemly weed in the base of our thoughts. We begin to fear strengthening those new relationships presented for fear of loss, and also cling obsessively to those that have weathered time. With growing imminence, we know....that our time is coming.
Do we wonder when, do we wonder how or why?