I don't like running when I'm holding things in my hand, whether it's a dog leash or a baby jogger. My mechanics get all messed up.
If you put a baseball and other toys in front of a baby, he'll pick up a baseball in preference to the others.
I was working part-time as a cleaner while I was going to college and then babysitting after school.
The actual organization of behavior goes on the level of the individual nerve cells and their connections, and we have a hundred billion nerve cells, probably a hundred trillion connections. It's just mind-boggling to think of all the different ways in which they're arranged in a baby's head.