French and impressive as thought by Del Boy from British television sitcom "Only Fools and Horses".

Direct French translation is Shower Cap.
Direct Spanish translation is Gorro de ducha

When you feel like sharing with others something you really like, you say "Bonnet de douche"

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.