What is the difference between you and my dad?
Nothing.
What is the difference between you and my dad?
Nothing.
Listen up, buttercup! The joke is that there is no difference between you and the author's dad. It's funny because it means the author is basically roasting you by comparing you to their dad and saying you're equally... well, you get it. You're probably not as smart as a doorknob, but hey, at least you're trying, right?