Again, I can’t remember what episode this is from. But maybe J. Lau does?
Here are some more of my favorite Hercule Poirot quotes (from the television series):
From “Elephants Can Remember”
From “Peril at End House”
Fictional Pears: Hercule Poirot Favorite Quotes
Angry Pear 
February 6, 2014 at 2:43 pm
This first one is from “The Mystery of the Spanish Chest”, the last line in that episode, though the second one is from “The Dream”, and the third is indeed from “Peril at End House”. I’d love for there to be a calendar or a booklet of Poirot illustrations!
February 6, 2014 at 7:06 pm
I knew you would know them! Thanks!