When a guy hasn't got the nerve to stick his finger or his cock inside the arse of a girl, but he spends a bit of time around her anus - testing for another time.

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.