"For you to be here now, trillions of drifting atoms had to assemble in an intricate and intriguingly obliging manner to create you. It's an arrangement so specialized and particular that it has never been tried before and will only exist this once. For the next many years, we hope, these tiny particles will uncomplainingly engage in all the billions of deft cooperative efforts to keep you intact and let you experience the supremely agreeable, but generally under appreciated state known as existence.

Why atoms take this trouble is a bit of a puzzle. They are mindless particles, after all, and not even themselves alive. It is a slightly arresting notion that if you were to pick yourself apart with tweezers one atom at a time, you would produce a mound of fine atomic dust, none of which had ever been alive but all of which had once been you. Yet somehow for the period of your existence they will answer to a single overarching impulse; to keep you you. The bad news is that atoms are fickle and their time of devotion is fleeting, fleeting indeed. Even a long human life adds up to about 650,000 hours, and when that modest milestone flashes past, for reasons unknown, your atoms will shut you down, silently disassemble, and go off to be other things. And that's it for you. Still, you may rejoice that it happens at all. Generally speaking in the universe it doesn't, so far as we can tell. Whether or not atoms make life in other corners of the universe, they make plenty else, indeed they make everything else. Without them, there would be nothing, nothing at all. So thank goodness for atoms. But the fact that you have atoms and that they assemble in such a willing manner is only part of what got you here.

To be here now, alive in the twenty-first century, and smart enough to know it, you also had to be the beneficiary of an extraordinary string of biological good fortune. Survival on Earth is a surprisingly tricky business. Of the billions and billions of species of living things that have existed since the dawn of time, most, 99.99%, are no longer around. Life on Earth, you see, is not only brief, but dismayingly tenuous. Not only have you been lucky enough to be attached since time immemorial to a favored evolutionary line, but you have also been extremely, make that miraculously, fortunate in your personal ancestry.

Consider the fact that for 3.8 billion years, a period of time older than the Earth's mountains, and rivers, and oceans, every one of your forebears on both sides has been attractive enough to find a mate, healthy enough to reproduce, and sufficiently blessed by fate and circumstances to live long enough to do so. Not one of your pertinent ancestors was squashed, devoured, drowned, starved, stuck fast, untimely wounded, or otherwise deflected from its life's quest to delivering a tiny charge of genetic material to the right partner at the right moment, in order to perpetuate the only possible sequence of hereditary combinations that could result eventually, astoundingly, and all too briefly, in you."

~Taken from "A Short History of Nearly Everything" by Bill Bryson

This quote often takes me out of my element, usually when I'm feeling sorry for myself for whatever problem or perceived wrong I'm facing at the moment. It doesn't say much more than "you're unique", however unlike that phrase it explains exactly why.