Our "powers of recovery," are amazing. Knock us down, we can get back up. Expend lots of energy, somehow, it all comes flooding back. You wonder where it comes from. And you wonder if this power will always work. You know, you find yourself in a deficit of energy, but you recover, again and again, until one day you don't.
There are limits. You won't grow back a severed limb. Lose a finger, it's gone. Still, it's true, just like that old watch, we can "take a licking and keep on ticking." It's a power! Recovery!