Fluid Dynamics

I've been trying to track the changes motherhood has made in my brain.
For instance, I cannot suffer sad music or dark movies anymore. Nothing but comedy and frothy pop tunes for me. If it's going to make me feel, no thanks; reality more than suffices.
I started thinking whether this is dumbing me down, so to speak. It seems to me that mothers are sometimes 'dumb' like that, I mean we do spend a lot of our time with people whose intelligence falls far short of our own. We can't help but reduce ourselves. It's how we create a common language and a bond with our charges.
Be that as it may, I really hate the thought of getting dumber.
But then I realized, no, motherhood makes you smarter too. So many puzzle pieces start to fit together when you have kids. Epiphanies roll in heavily as boulders, ones you can't ignore, especially when they crush you. Your parents, perhaps your childhood, come steadily into focus, like a fuzzy image being tuned. I understand my parents' relationship a whole lot better, for one, and thus my own. So many more mirrors have come into view, and so many more will, as I go on losing myself in this funhouse maze. It can be depressing, frightening, and incredibly lonely, but undoubtedly life has become exponentially more interesting in the last five years.
Still, something is lost. Not long ago my son and my mother did an experiment. A cup of water next to an empty cup, a strip of paper towel acting as a bridge between them, one side dipping deep into the water. Before long the cups were both half-full. My mother was trying to show my son simple fluid dynamics: You can't keep all the water in the first cup once it has been breached, and you can't control or hinder the flow of water into the other cup. Just as dividing cells will continue to divide, just as sure as time passes, the water will drain, flow, fill. Join another empty cup and it diffuses further, and further with every empty vessel you add to the chain.
That's just plain physics.