Hercule Poirot: I am an imbecile. I see only half of the picture. Miss Lemon: I don't even see that.

The popular idea that a child forgets easily is not an accurate one. Many people go right through life in the grip of an idea which has been impressed on them in very tender years.

I really cannot understand the point of what you're saying. Really,' said Clotilde, looking at her. 'What a very extraordinary person you are. What sort of a woman are you? Why are you talking like this? Who are you?' Miss Marple pulled down the mass of pink wool that encircled her head, a pink wool scarf of the same kind that she had once worn in the West Indies. 'One of my names,' she said, 'is Nemesis.' 'Nemesis? And what does that mean?' 'I think you know,' said Miss Marple. 'You are a very well educated woman. Nemesis is long delayed sometimes, but it comes in the end.

There is no detective in England equal to a spinster lady of uncertain age with plenty of time on her hands.

Words, mademoiselle, are only the outer clothing of ideas.

Vous eprouves trop d'emotion, Hastings, It affects your hands and your wits. Is that a way to fold a coat? And regard what you have done to my pyjamas. If the hairwash breaks what will befall them?' 'Good heavens, Poirot,' I cried, 'this is a matter of life and death. What does it matter what happens to our clothes?' 'You have no sense of proportion Hastings. We cannot catch a train earlier than the time that it leaves, and to ruin one's clothes will not be the least helpful in preventing a murder.

I know there's a proverb which that says 'To err is human,' but a human error is nothing to what a computer can do if it tries.