I'm considering the difference between "evolution" and "evolution by natural selection". OK, I'm done now.

And now for something completely different...
"Laws" of nature, or the way things work. We often know there's something going on. We know the what but not the why. For example, fibonacci. Did this simply happen once, and work, so it kept working in other cases? Was it built into the universe at the time of the big bang? Where did it start, unless it always just was?