Leonard Shelby: I have to believe in a world outside my own mind. I have to believe that my actions still have meaning, even if I can't remember them. I have to believe that when my eyes are closed, the world's still there. Do I believe the world's still there? Is it still out there?. Yeah. We all need mirrors to remind ourselves who we are. I'm no different.
Natalie: Is that what your little note says? It must be hard living your life off a couple of scraps of paper. You mix your laundry list with your grocery list you'll end up eating your underwear for breakfast.
Leonard Shelby: Facts, not memories. That's how you investigate. I know, it's what I used to do.
Leonard Shelby: Memory can change the shape of a room; it can change the color of a car. And memories can be distorted. They're just an interpretation, they're not a record, and they're irrelevant if you have the facts.
Teddy: You're not a killer. That's why you're so good at it.
Leonard Shelby: I meet Sammy through work. Insurance. I was an investigator. I'd investigate the claims to see which ones were phony. I had to see through people's bullshit. It was useful experience, 'cause now it's my life.
Leonard Shelby: Now... Where was I?
Leonard Shelby: You know, I can remember so much. The feel of the world... Her. She's gone. And the present is trivia, which I scribble down as fucking notes.
Teddy: So you lie to yourself to be happy. There's nothing wrong with that. We all do it.
Natalie: You sad, sad freak. I can say whatever the fuck I want, and you won't remember. We'll still be best friends. Or maybe even lovers.
Teddy: You know, I've had more rewarding friendships than this one. Although I do get to keep telling the same jokes.