Sympathetic complementary oscillations of the cranium

Young man did something that totally floored me a couple of days back. 

It was a less than 3 days since his arrival and I had just finished feeding him and in an effort to burp him, I held him up, with his head on my right shoulder. As I rocked to the left and right, i noticed his head also move even as I supported it with my right hand. 

For an instant I thought it was just me and my movements that gave me the illusion of his movement. but then, when I looked at him, his eyes were open and he was looking at something.... 

Then I started rocking again and this time paid attention - he was actually turning his head in unison with my rocking as though to keep looking at the window behind me !!!!!!

I am floored. I did not expect a 72 hour old baby to have sufficient neck muscle strength or the coordination to complement my motions.... Surrendaar !