What do you know about?

We all know something. We might not know about the ancient world yet, but we do know something. So what do you know? I know a lot about the ancient world, shingling, Google Drive, sports, computers and Game of Thrones. I bet you know something that I don't. I bet you know a lot about something. So, let me as you this, what do you know a lot about? 

Task: Share with me something you know about. What topic are you an expert on? Tell me all about something you know about.