Why do we remain babies when it comes to our mothers, even as grown men?

Even though I've become a 35-year-old man, I still love my mother's physical affection so much.
I still love it when she taps my belly, pats my butt, or gives me a little pat on the rear.
I wonder if it's because she's my mother... Both she and I have aged a lot and our faces have changed significantly since we were children, but I still love her touch so much.
It makes me think that if she were to pass away someday, I would miss that deeply.