An unexpected question

Today, as I was driving the boys back from school, Owen asked me how the earth was made. Lately, he's been asking a lot of questions like this, such as "where does corn bread come from?" or "where do flowers come from?". I have to admit, this one threw me for a second. I paused and started to tell him that there are a couple of theories that exist. Luckily, before I had to explain in detail, he continued to tell me that that the earth goes in circles around the sun and at the same time he started to make circles with his fingers in the air. Then he explained that earth moves around the sun and makes morning and night. A second later, as we were pulling into our neighborhood, he happily switched topics to start telling me about what house and neighborhood he thinks his friend lives in. I just shook my head and marveled. Just weeks (okay days) ago we were immersed in poop talk. Now, we are on evolution? God, help me.