Stole from my sister

I did something really bad and I can't tell anyone I know. When I was like, 10 or 11, my older sister had this really cool necklace. It was silver, with a little blue stone. I was so jealous. One day, I went into her room and just took it. I wore it a bunch, but hid it whenever she was around. She asked me if I'd seen it, and I said no. She was so sad. Eventually I got bored with it and just threw it away in a trash can at school. I still feel guilty about it, even though it was like 20 years ago. I was such a brat. I wish I could tell her, but I'm too ashamed.