You shave your pubes and keep the trimmings. Then, later that night, you jizz a mustache on a girl and sprinkle the cut pubes on her face

A phrase to describe someone who is cognitively degenerating. Synonym of "going off the deep end". Can have varying degrees of severity.

Reference to the song "Hey You" by Pink Floyd. The line "and the worms ate into his brain" makes no sense in an otherwise linear and literal narration throughout the lyrics.