Sometimes you get to witness almost the exact moment that your child's brain added a few new rooms. In Jackson's case, it added The Monkey Room.
They say that for a while when you leave the room, you no longer exist to a baby. Of course, as they get older they remember and realize things exist outside of their 18 inches.
Object permanence and so forth.
Jackson has grasped the idea of people being elsewhere a long time ago. But this weekend school has become another place where he might be at some point. He realizes it exists outside of home.
He has understood the concept of school for quite some time but this weekend school became a location useable in conversation. If something is not at home, then it must be at school.
Jackson, where is your sippy cup?
Hey Jack, where did your mittens go?