It is easy to overlook this thought that life just is. As humans we are inclined to feel that life must have a point. We have plans and aspirations and desires. We want to take constant advantage of all the intoxicating existence we've been endowed with. But what's life to a lichen? Yet its impulse to exist, to be, is every bit as strong as ours - arguably even stronger. If I were told that I had to spend decades being a furry growth on a rock in the woods, I believe I would lose the will to go on. Lichens don't. Like virtually all living beings, they will suffer any hardship, endure any insult, for a moment's additional existence. Life, in short, just wants to be. But - and here's an interesting point - for the most part it doesn't want to be much.
A Short History of Nearly Everything, by Bill Bryson