When my son was about 5 he was sitting in his car seat looking first very thoughtful, and then pleased with himself.
He said, "Daddy, I know something I've got more of than you do."
Me:"What's that?"
Him: "Ancestors! You are my ancestor, and all of your ancestors are my ancestors, so I have more ancestors than you do."

When my daughter was 15 she came home from school very excited and said, "We're going to do a driver education course at school!"
I asked, "Will you be using a car at all?" and she said "No."
I said, "A driver ed course without a practical component isn't so much use."
Becoming cross, she said, "Well, I'm sure you'll be relieved to know that there isn't a practical component in our sex ed course, either."
Silence from Dad.