Confession of the day:
I have a "mom arm."
It doesn't matter if there is no one sitting in my passenger seat. It doesn't matter if it's a bag of groceries. Or a backpack.
It doesn't matter that I know it will have almost no effect in the event an incident occurs. And it doesn't matter how hard I try to override this automatic response.
When I apply my brakes in a sudden fashion while driving, my right arm flies out to protect whatever is (or is not) occupying space in my passenger seat.
The mom arm. I've got it bad.