My DS (3 yrs.) just started learning his first Catechisms.  The first two are: 

1.  Who made you?  God.

2.  What else did God make?  God made all things.

He was very excited about what he had learned and wanted to show his big sister (5) that he had memorized it.  I asked him the second question and he said "Alll things." then sis said "God didn't make all things.  God didn't make houses, people make houses."  Then he came back with "NO, God made all things!"  Back and forth they went, louder and louder they got.  My DH and I were laughing b/c they were so darn cute and really serious.  We couldn't say anything until we got our composure. 

I remembered when my DD was this age and learning the same catechisms, and she would say that God made houses.  She has a memory like an elephant, so when we explained to her that people made houses and God made the parts that help make the house - she remembered!

As I was putting DS to bed, we were going over the catechisms again.  He made sure to let me know that God made ALL THINGS ;) and he knew what he was talking about.