Just like no one knows the exact day a child will be born,so also no one knows when he/she will die.
But we should all live everyday like its our last,enjoy every moment and live a life that is pleasing to God.
coz if someone claims that I may live a long life,
i can just prove him wrong by slicing a knife on my throat
i may die, thus proving him to be false
well, thats a pretty bad idea to try