Screen Door Accident

Alright listen up buttercup, this joke is about a leper, a person with leprosy which is a disease that causes your skin and nerves to get damaged. When the leper walks into the screen door, he "strains himself". But get this, it's a play on words! Because folks with leprosy lose sensation in their limbs, so instead of "straining" himself he would have to "restrain" himself from ripping his limbs off. I bet you didn't think about that, huh? Probably cuz you are a bonehead!