Expressions in Tim Minchin's “Storm”

Question

Can you help me with these expressions from Tim Minchin's Storm? There will be some obscenities—sorry for those; I am just interested in their meaning.

• "I confess a pigeonhole starts to form" [1:10]
• "diplomacy dike" [2:55]
• "What are we - fucking two" [4:55]
• "Horton heard a who" [4:55]
• "Blow your hippy noodle" [7:12]

Answer 1

• "I confess a pigeonhole starts to form": This is referring to the third definition of pigeonhole here, "a neat category which usually fails to reflect actual complexities". He is saying that he is beginning, in his mind, to ascribe to her the characteristics of a particular stereotype (the details of which become apparent later on). The term comes from the use in offices of shelves with compartments for different types of form - so there will be a pigeonhole for form 43A, and another for form 66C; the term is also used in UK offices for what I believe in the US would be called a mailbox. Of course this in turn comes from its physical resemblance to the original meaning, "a hole for pigeons to live in".

• "diplomacy dike": He is using the word "dike" (spelt "dyke" in the UK - that is not an error in the subtitling!) in sense 2b here: a barrier or dam to hold something undesirable back. By "diplomacy dike" he means his diplomatic self-restraint, which generally serves to keep his tongue from voicing his insulting thoughts, and in this case is holding back a barrage of abuse (that comes out later in the poem).

• "What are we - fucking two": He means "two years old". The word "fucking" here has no semantic content, it merely serves to emphasise his anger and frustration.
• "Horton heard a who" This is a reference to the name of a childrens' book, continuing in the theme of comparing the girl to a two-year-old. This book is particularly apt, because the main character claims the existence of phenomena that nobody else has observed, and is ridiculed for doing so, yet stands up for it.
• "Blow your hippy noodle": This combines two idioms - "noodle" as a slang term for "head", and the phrase "blow (someone's) head" (or "blow (someone's) mind"), meaning (roughly) to massively surprise them / hugely challenge their expectations and beliefs (the image is that the concept will actually make their head explode). The word "hippy" (often spelt "hippie") is his description of her worldview, and by extension her head.