Here's an exchange that took place in our house yesterday that suggests that my kids tend to think of more abstract concepts in ruthlessly literal terms (at least in the early years). Also, I'm not sure this way of thinking about the mind is entirely incorrect.
But what can I DO???
You can play with your imagination.
(after a moment of reflection)
But I don't want to play with my brain.
If I take it out, everything I'm thinking will fly away.
I feel the same way about my brain and the things I'm thinking, son. The exact same way.