1) An insult referring to ones poor judgement, lack of intelligence, or inferiority due to poor genetics.

2) Not being born into a wealthy or decent family.

3) Someone conceived as a result of cheating or inbreeding.

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.