Ha, I tried out that "your brain is a muscle" approach with DS8 on the way to school yesterday. His response: "Mom, your brain is NOT a muscle, it controls all the muscles in your body, but IT isn't a muscle!" So, it didn't work for me! lol Guess I should have stated more clearly that it's an analogy.

We settled on talking about getting synapses firing and "lighting up" your brain by learning new things and taking on challenges. This made more sense to him, but I am not sure that this approach would really affect how he thinks.