They are strange.
My 5yo just spent 15 minutes telling me about Yin Yan Yoh, who is apparently a super bunny, who fights evil with his powers. I believe I got that right. This after he ran around the kitchen with his head in a strainer yelling "Crazy Taxi, crazy taxi" Hmmmm.
My 12yo, who is supposedly bright and mature just explained why it is not his fault the ball bounced off the glass door of the china cabinet. He was aiming for the piano after all. Gee, that makes it all better. What was I thinking?
10yo. Well, he is just generally strange.