"It is my experience that no one, in the course of conversation, can fail to give themselves away sooner or later. Everyone has an irresistible urge to talk about themselves."

"No one human being knows the full truth about another human being."

"It is completely unimportant. That is why it is so interesting."

"If you confront anyone who has lied with the truth, he will usually admit it - often out of sheer surprise. It is only necessary to guess right to produce your effect."

"I have always been a great admirer of Miss Marple."