Paper stars flutter to and fro in time to the rhythm of the air conditioning. A wall of black plastic sits beneath reams of masking tape and fluorescent post-it notes. It’s masquerading as the New York City skyline. This is Pinterest’s creation come to life. This is the middle school’s eight grade dance. I set it up and now I wait for the children to arrive. I chaperoned this event for Sean when he was in eighth grade. At the…