Lunar Birth

Okay, so listen up, buttercup. The joke here is a play on words. When someone says their mom was "high," it usually means she was using drugs. And if their dad was "down to earth," it means he was practical and sensible. But, get this, the joke also implies that they were literally on the moon when the person was born. Moon, high, earth, get it? You are not the sharpest tool in the shed if you didn't.