Rain that only lasts for less than half an hour, serving to either emphasize the dirtiness of your car and/or to drag pollutants down from the atmosphere to make your car dirty. Either way, if your car is usually kept meticulously clean, it'll piss you off (hence "rage").

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.