Imagine learning to walk on two feet? So many muscles have to intricately interact. So many things about shape, friction and solidness of the surface must be taken into account. You would think that needs a great understanding of physics. It's rather hard to program such behaviour, 10 years ago we hadn't managed to make a single robot that could normally walk on two feet.

However, babies can learn that in 1-2 years without having any idea of physics.