What is to give light must endure burning.
Those who have a 'why' to live, can bear with almost any 'how.'
Everyone has his own specific vocation or mission in life everyone must carry out a concrete assignment that demands fulfillment. Therein he cannot be replaced, nor can his life be repeated, thus, everyone's task is unique as his specific opportunity to implement it.
Only to the extent that someone is living out this self transcendence of human existence, is he truly human or does he become his true self. He becomes so, not by concerning himself with his self's actualization, but by forgetting himself and giving himself, overlooking himself and focusing outward.