This book I'm reading brought up an interesting concept. It describes an evolutionary turning point in the human brain… a moment, when pre-modern humans experienced an explosion of creative behaviors and adaptations. The details get a bit complicated, discussing various environmental factors and capacity for symbolic reasoning, but here's the gist.
While other living creatures adapt to their environments, humans developed the ability to adapt to "change" itself.
If you drop a man into the domain of another equally-sized, specialized animal, and take away his ability to use weapons or tools, he's going to lose. His claws are no match for the mountain lion. His teeth are no match for the wolf. His swimming is no match for the shark. His running is no match for the cheetah. He's not specialized to live in any given place.
But when circumstances change, he can recognize it and adjust accordingly. And since change is pretty much guaranteed, that's a big deal. How big? Well, we're 7 billion strong and growing. It turns out that when drastic change is constant, investments in biological software are more important than investments in hardware.
Just food for thought, next time you find yourself resistant to the next big change in your life.