- Creator Backlash: Agatha Christie got tired of writing his novels, describing him in 1930 as "insufferable" and in 1960 as a "detestable, bombastic, tiresome, ego-centric little creep". However, since she saw how popular the character was, she felt the obligation to continue giving his fans more Poirot stories, which she did until 1975, one year before her death.
- As the quote at the top of this article suggests, Agatha Christie much preferred her other character, Miss Marple.
- In-universe in Mrs McGinty's Dead, Adriane Oliver delivers nearly the same quote when talking about her own character, a Finnish detective with a bizarre quirk (he grates his vegetables before eating them).
- Referenced by...: In Sir John Magill's Last Journey (1930) Inspector French remarks to a colleague "use your grey cells, as that Belgian would say."
- Trope Namer: For...
Trivia / Hercule Poirot