Next time you are waiting in line at the grocery store, look around and see if you can spot a woman who is, ever so slightly, swaying from side to side. This woman is a mother. How do I know this? I know this because she has spent so much time rocking a baby at home that she does it automatically any time that she is not sitting in a rocking chair. Since having children, I think I am incapable of standing still. When I find myself standing, with or without a child in my arms, I start moving before too long. Movement is comforting to babies and even toddlers and, after a while, it becomes comforting to mommies too.
So, now I promise you two things: one, you will notice a woman standing alone and swaying at some point; two, you will laugh because you know I am right.