Et in arcadia ego

 "Man that is born of a woman is of few days and full of trouble.
 He cometh forth like a flower, and is cut down: he fleeth also as a shadow, and continueth not."
 
It was Euripides who observed that no one can confidently say that they will be living tomorrow. Shakespeare, through the words he paced in the mouth of Hamlet, explained the implications:
"If it be now, ’tis not to come. If it be not to come, it will be now. If it be not now, yet it will come—the readiness is all"

"It is not death that a man should fear, but he should fear never beginning to live." - Marcus Aurelius