When , during and particularly energetic bout of sexual intercourse, you withdraw the knob a little too far and when attempting to re-enter the otters pocket it is deflected into the chocolate speedway

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.