Given that someone before had offered a compelling Christian perspective, I shall give the existentialist perspective on the same matter.
"The gods had condemned Sisyphus to ceaselessly rolling a rock to the top of a mountain, whence the stone would fall back of its own weight. They had thought with some reason that there is no more dreadful punishment than futile and hopeless labor."
- Albert Camus, from "The Myth of Sysiphus"(http://en.wikipedia.org/wiki/The_Myth_of_Sisyphus)
Existentialists such as Camus or Satre would tell you that the universe is an "absurd" and cold place, dictated by the physics of clashing atoms, indifferent to human ideals such as compassion and justice. Human life is "absurd" because while some may subscribe to hedonism to escape the indifferent reality, while other follow some arbitrary set of institutionalized ethics for either hopes of after-life or external validation from society - when the facts remain, everyday we are one day closer to our death, which spells the ceasing of our consciousness and hence, the ceasing of any meanings of our lives because the lofty ideals such as the difference you made for your kids, your family, your community are still "absurd" man-made ideals (just ask the loyal GM employees who've been laid off, or a recently divorced person).
Much of our existential anxiety derives from our reluctance to confront our "absurd" reality or to make it "un-absurd" (i.e., we think that life's unfair, we can code better than Mark Zuckerberg in php and if we were at the right place and the right time, we could have been the Facebook billionaire; so we are going to work hard now, at another Web 2.0 startup). When, in fact, it's just that only in an "absurd" universe's arbitrary lottery, Zuckerberg hits the power ball while you are relegated to mundane, boring 9-5 code monkey job for the rest of your life - no matter how harder you work or how smarter you are than Zuckerberg. Eventually, by your failures alone, you'll begin to even doubt that you are not as smart than Zuckerberg.
Sounds depressing? But Camus/Satre would say, only truth could set you free (besides you always knew it in the back of your head). The world is an indifferent, uncaring place - it sounds horrible, but it means you alone are in control of the meanings in your life.
"Taking the absurd seriously means acknowledging the contradiction between the desire of human reason and the unreasonable world ... The contradiction must be lived; reason and its limits must be acknowledged, without hope. However, the absurd can never be accepted: it requires constant confrontation, constant revolt."
In the end of his essay, Camus declares that "we must imagine Sisyphus happy" for his action of trying to defy death and the gods should by itself satisfy him (gods condemned Sisyphus to his futile labor because he defied death). Translated to startup's or any other modern endeavor, we must confront with the absurdness of our fate (probability says that you will never win the Nobel Prize, start up, literary lottery) but yet constantly defy the "absurdness" (keep trying hard at our goals anyway), because the mere act of constantly trying to defy the universe and create our own values is in of itself meaningful and satiating.
"The struggle itself towards the heights is enough to fill a man's heart."