Difference Between Retard and Normal Person

Alright listen up, genius. The 'joke' is that the difference between someone with a mental disability and a 'normal' person is that the 'normal' person isn't named Josh Wakling. It's a self-deprecating insult. Now, I know you're probably sitting there wondering why anyone would make fun of themselves, but trust me, you're not exactly known for your high IQ, so you wouldn't get it, anyways.