"It often seems to me that's all detective work is, wiping out your false starts and beginning again." "Yes, it is very true, that. And it is just w… - Agatha Christie

They conceive a certain theory, and everything has to fit into that theory. If one little fact will not fit it, they throw it aside. But it is always the facts that will not fit in that are significant.

I'm used to that. It often seems to me that's all detective work is — wiping out your false starts and beginning again.

Give up the past! Turn to the future! What is done is done. Bitterness will not undo it.

"What are you doing, Poirot?"
"I dissect rucksacks. It is very interesting."

"Life can be very terrible," he said. "One needs much courage."
"To kill oneself? yes, I suppose one does."
"Also to live," said Poirot, "one needs courage."