In the eternal universe, every human being has a one-off chance to live -- his existence is unique and irretrievable, for the mold with which he was made, as Rousseau said, was broken by God immediately afterwards.
Fame, wealth and knowledge are merely worldly possessions that are within the reach of anybody striving for them. But your experience of and feelings about life are your own and not to be shared.
No one can live your life over again after your death. A full awareness of this will point out to you that the most important thing in your existence is your distinctive individuality or something special of yours.
What really counts is not your worldly success but your peculiar insight into the meaning of life and your commitment to it, which add luster to your personality.
It is not easy to be what one really is. There is many a person in the world who can be identified as anything either his job, his status or his social role that shows no trace about his individuality.
It does do him justice to say that he has no identity of his own, if he doesn't know his own mind and all his things are either arranged by others or done on others' suggestions; if his life, always occupied by external things, is completely void of an inner world.
You won't be able to find anything whatever, from head to heart, that truly belongs to him. He is, indeed, no more than a shadow cast by somebody else or a machine capable of doing business.