Is it down to rote memorization?

I understand there is a method to the madness of the scales, a pattern which defines them.
But is knowing how to play any of them at a moment's notice just a matter of doing them enough that you're pretty much driven by muscle memory? I'm wondering if there's pattern I'm supposed to know that helps me remain aware of how to finger them as I play, or if it's just plain old knowing that this one ends on finger four and that one doesn't and doing all of them so often that it's a matter of reflexes. Which isn't a problem, there's lots of complex things I do in my day where I don't have to think about each individual motion, like driving. I remember how hard driving seemed at first. Is playing scales the same way?

Yes, playing scales is exactly the same as drive, get's easier as you do it more.

I even relate a scale to driving a car on a highway vs off road to my students in real life. You want to drive completely smooth and horizontal, not vertical, keep any movement of your arm bumping up and down to a minimum. Practise it 300 times and you will start to feel comfortable doing it