I think it's about this boy. She knows everything about and he most likely doesn't see her. She thinks about him every minute and he tells her stuff he shares with noone else. She's probly anting him to know how she fells by telling him I simily know everthing about you. And the meaning of I'd lie is becuase ex: Do you like Ricky? No! Taylor lies insted of telling her true feelings. A great way to show she loves him but in a way that's say Maybe I do maybe I don't. Trust me! I'd lie!