Sheldon: And early trains used the drop chute toilet, also called the hopper toilet, which was really just a hole...

Missy: What's it like to not believe in God?
Sheldon: It's great. Big fan.
Missy: Are you ever afraid you're wrong?
Sheldon: About religion? Never. About other things? Also never.

Ms. MacElroy: Now, can anyone tell me why Melville shifts the narrative voice from Ishmael to Ahab? [Ms. MacElroy waits for somebody else to raise their hand] Sheldon.
Sheldon: I have a tummyache. I'd like to see the nurse.
Derek: A "tummyache"?
Sheldon: Yes, Derek, I have a tummy and it aches. Ergo, tummyache.
Derek: Ergo?
Sheldon: It's Latin, Derek.
Ms. MacElroy: Go to the nurse.
Sheldon: And to answer your question, the shifting point of view grants the reader a broader perspective of events than typically allowed by first-person narration.
Ms. MacElroy: Where were we?
Sheldon: And "ergo" is Latin for "hence," Derek.

Mary: Sheldon, faith means believing in something you can't know for sure is real. And right now, I am struggling with that.
Sheldon: So you don't believe in God anymore?
Mary: That isn't something for you to worry about. I need to figure this out myself.
Sheldon: Can I help? Maybe I could provide a fresh perspective.
Mary: I don't think so, baby.
Sheldon: Did you know that if gravity were slightly more powerful, the universe would collapse into a ball?
Mary: I did not.
Sheldon: Also, if gravity were slightly less powerful, the universe would fly apart and there would be no stars or planets.
Mary: Where you going with this, Sheldon?
Sheldon: It's just that gravity is precisely as strong as it needs to be. And if the ratio of the electromagnetic force to the strong force wasn't one percent, life wouldn't exist. What are the odds that would happen all by itself?
Mary: Why are you trying to convince me to believe in God? You don't believe in God.
Sheldon: I don't, but the precision of the universe at least makes it logical to conclude there's a creator.
Mary: Baby, I appreciate what you're trying to do, but logic is here. And my problem is here.
Sheldon: Well, there are 5 billion people on this planet and you're the perfect mom for me. What are the odds of that?

Adult Sheldon: Presenting... "Sheldon Cooper's Top Five Sources of News From My Childhood". Number five: Star Trek Fan Club Magazine.
Sheldon: Mom, DeForest Kelley's favorite episode is "The Empath."
Mary: Good to know.
Adult Sheldon: Number four: the Weather Cube from RadioShack.
Man: [from device] The humidity is 90% with a dew point of 79.5 degrees.
Sheldon: Mom! The dew point is 79.5 degrees.
Mary: [o.s.] Okay.
Adult Sheldon: Number three: The MacNeil/Lehrer NewsHour. Such a great theme song.
Sheldon: [hums] Buh-buh-bum.
Adult Sheldon: Number two: Meemaw after a few beers.
Meemaw: It took a while, but we finally picked a new name for my bowling team: The Ball Busters.
Sheldon: Hey, Mom. Guess what Meemaw named her bowling team? The Ball...
Adult Sheldon: And the number one source of news from my childhood: the bulletin board at the train store. News about trains in a store full of trains. Yummy.
Sheldon: How did this not make The MacNeil/Lehrer NewsHour?

Meemaw: Alls I'm saying is people aren't always in the mood.
Sheldon: Well, they should be. I'm happy to learn any fact at any time.
Meemaw: Is that so?
Sheldon: Yes.
Meemaw: Grab my knitting bag.
Sheldon: I don't recommend driving while knitting. Your reflexes aren't what they used to be.
Meemaw: Just look in the bag! Did you know that there are three different kinds of yarn?
Sheldon: I didn't.
Meemaw: You got your animal, like wool. Your plant, like cotton. And your synthetic, like acrylic.
Sheldon: Interesting.
Meemaw: You think so? I'm glad to hear that. Because each one of them has plusses and minuses, and you're about to hear them all in mind-numbing detail.

Mary: [eating pop corn] Get him, Dalton. Get him.
George Jr.: Mary Cooper, what are you doing?
Mary: Nothing.
George Jr.: Why are you watching Road House?
Mary: Why aren't you at work?
George Jr.: I asked you first, and my question is way more interesting.
Mary: It was just on. I don't even know what that is.
George Jr.: Then how'd you know his name's Dalton?
Mary: I don't have to explain myself to you.
George Jr.: This is a pretty dirty movie.
Mary: How do you know? It is rated R.
George Jr.: For violence, language and sexual content. You should be ashamed of yourself.