The foremost excuse in the frequent case when something that is supposed to happen doesn't; notably, when a person who promises you something doesn't fulfill the promise. The absence of a key component or ingredient is an unarguable reason why you didn't get what you wanted.

Like all excuses, There Isn't Any is a true statement (although you can't prove a negative, you can search the cupboard or the stockroom and see that There Isn't Any, if you want to be a dick) which evades all discussion of why There Isn't Any; above all, why no one did his job and planned ahead so that there might be some.

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.