I kept my paper ticket for a week out of habit

My first week, I walked into Union Station with a paper ticket in my hand, the way you do where I come from, and looked for the machine to stamp it. There was no machine. People just tapped a card on a small reader and walked through, and on the streetcar the driver did not even look up. I kept the ticket in my pocket for days, in case someone asked. Nobody did. Everyone had stopped hearing the little beep a long time ago, and I could not stop hearing it.