You're with the group when someone says a word, or a name, or a random phrase — and everyone cracks up. Everyone except you. It's an inside joke from a time you weren't there, about something you don't know. And in that moment, surrounded by laughing people, you feel completely on the outside. You laugh a little anyway, fake, so you don't look left out. But it lands in your stomach: there's a whole history here that you're not part of. They have a shared past, and you're a guest in it. Everyone's still laughing. You're smiling. And you've never felt more alone in a crowd.