When we are born our clock begins. Each new person has begun. There is growth in the first period of years, then at some time during middle age the count down begins. We, each one of us, steadily begins to deteriorate. Finally, something important within us stops working and we die. The clock stops.
This is more or less the normal sequence. It is not guaranteed and it may be interrupted or halted at any moment. There may be unpredictable influences that alter the norm. Things like genetics, bad luck, and accidents for example. But for most of us our lives will follow the course of the ticking clock.
Bill Gates has famously said:
"Life is not fair. Get over it".
No matter how profound and no matter how correct - when we see hungry children without clothing or shelter we ask:
"Why are we so fortunate, and why are they not?"