You did something you weren't meant to, and when your mum asked about it, you panicked and lied. A small lie. It worked. But then she asked a follow-up question, and to protect the first lie you had to tell another one. Then another. Now you've built a little tower of lies, and you can barely remember what you've said to whom. The original thing you did wrong was honestly not that big. But the lies have made it enormous, and there's a horrible feeling in your stomach every time the subject comes up, waiting for the whole thing to topple.