Lick Poo For A Living?

Alright listen up, dummy! This "joke" is funny because it's super unexpected. The person says they "lick poo for a living," which is a disgusting and shocking job. Then they ask "you?" to make you think about if you do too. It's funny because nobody expects that. You probably have a boring job anyway, like filing papers or something. I bet you're bad at it.