Things kids say

Little Dude picked "I Love You Forever, I Love You for Always" as his bedtime story tonight.  All three boys sat in his bed while I read it.  I tried to emphasize that I did that when they were new babies, I too had rocked them "back and forth, back and forth" like the Mother in the book.  We got to the end of the story and Munchkin says, "I'm going to be a Dad soon."  (I don't doubt he'll be a wonderful Dad and he already loves babies to bits, but don't see Dad-hood in his immediate future at 5 years old.)  "Really?  Well, I hope not too soon because you've got lots to do before you become a Dad."  Little Dude then pipes up to say, "Well, I'm going to be a teenager soon."  I said, "Don't you think you should be 9 first?"  (In the story the little boy is 9 before he's a teenager.)  "I'm 2 heads away from being a teenager."  He reasons, and then informs Munchkin, "You're 3 heads away."  I don't know if he means height wise or....is there another way to mean this??...Love watching the logic develop.