Yesterday, my youngest girls played with Barbie dolls in the pool, which is still filling. It was extremely hot, so I let them wade and play while we tried to fill it to a reasonable height. Katie watched them and then mentioned to me that when she was 3-4 years old, Amy would only play Barbies with her if Amy was allowed to chose how they played. Amy is 5 years older than Katie and had just read The Diary of Anne Frank. Poor Katie was forced to play "Gas Chamber" with Amy. Their dolls were always hiding from the people who wanted to throw them in the gas chambers. Katie just realized that she had been playing holocaust.
I'm always amazed at the amount of carry-over from lessons or readings that my children bring to their play. After all these years, I should be prepared for these glimpses of learning, but they always surprise me. I should also do a better job of seeing what they are playing, especially when it's quiet.