Wow, there sure is a lot of pseudo-profound intellectual masturbation in this thread... Seriously, I won't name anyone but some of you might want to consider to stop trying to sound "deep" and actually research and find the answers that are available.
The problem with "why" questions is that it stems from the notion that everything has an intention behind it. It's mostly true when it comes to human affairs (hence the existence of such a notion), but it's not the same in nature. We can ask how humanity, or life, came to be. The simplest answer would be "emergence". But "why"? There is no reason, it's just part of the progression of the Cosmos. If you want to find out about our origins, you'll have to look into evolutionary biology, genetics, abiogenesis, astronomy, physics,... It will take you more than a few days to be honest. If you're searching for an outside "validation", an objective view that would classify your existence as worthwhile, then good luck with that. I don't think it'll ever happen, and I couldn't care less. I am the only consciousness I'll ever know, and I think my existence is valid.
Asking "why" is anthropomorphizing the cosmos, it's the most intuitive view (judging from thousands of years of religion) but it's simply not productive.
As Jean-Paul Sartre would put it: "Existence precedes essence."