When the fact doesn't meet the theory then let go the theory.

I'm sure you have a theme: the theme of your life. You can embellish it or desecrate it, but it's your theme, and as long as you follow it, you will experience harmony and peace of mind.

Who are you? You don't belong to the police?' 'I am better than the police,' said Poirot. He said it without conscious arrogance. It was, to him, a simple statement of fact.

I looked at her. Sheila was my girl--the girl I wanted--and wanted for keeps. But it wasn't any use having illusions about her. Sheila was a liar and probably always would be a liar. It was her way of fighting for survival--the quick easy glib denial. It was a child's weapon--and she'd probably never got out of using it. If I wanted Sheila, I must accept her as she was--be at hand to prop up the weak places. We've all got our weak places. Mine were different from Sheila's, but they were there.

Sometimes I feel sure he is as mad as a hatter and then, just as he is at his maddest, I find there is a method in his madness.

Authors were shy, unsociable creatures, atoning for their lack of social aptitude by inventing their own companions and conversations.

I know nothing about pistols and revolvers, which is why I usually kill off my characters with a blunt instrument or better with poisons. Besides, poisons are neat and clean and really exciting... I do not think I could look a really ghastly mangled body in the face. It is the means that I am interested in. I do not usually describe the end, which is often a corpse.