"I don't know! About the walkers! And the prison, and the farm. Stuff that matters." She's not going to back down on this. He's snapping like she was supposed to know he wanted the end of the world to be a secret. Just because she can tell what he's thinking, more often than not, doesn't mean she's a damned mind reader, especially when he was in a different camp altogether. "Nobody here understands anything. I had to tell them something."