We've been working with my daughter on anger and worry, and since she's such a reader we found her some books that might help. They seem really good but she's not too excited about reading them. No big surprise since she generally doesn't want to do the things we ask her to do.
Anyway though, I was talking with her about those books at bedtime and she asked me why the worry book has a tomato plant on the cover. I hadn't really noticed it or thought about it. She clearly had given it some thought because she came up with this great metaphor. She said "Maybe it's because worries are like tomato plants. If you think about them and water them they grow bigger and tomatoes grow, but if you forget about them or ignore them they kind-of shrivel up and die."
I asked her if that metaphor was from the book and she said no she hadn't read the book yet. Doesn't really matter either way, I'm proud of her for thinking of the metaphor and seeming to understand it.