Sheldon: [observing the older kids outside the high school] Oh dear.

Sheldon: Why do you keep smiling?
Mary: You need to look at your mask, baby.
Sheldon: Missy!

George: What's a modem do?
Sheldon: It allows me to connect my computer to other computers that also have one.
George: Why would you need to do that?
Sheldon: So I can share my scientific ideas with academics all over the world. It's like the cybernetic version of the Algonquin Round Table.
George: I don't know what that means.
Sheldon: That's okay, you're still my dad and I'm genetically obligated to love you.

Mary: Shelly, it's your last day of summer. Go out and enjoy it.
Sheldon: But I have to learn the student handbook. Ooh, did you know extreme hairstyles, goatees and mustaches are not allowed?
Mary: I didn't.
Sheldon: I personally find that very reassuring.

Missy: She's lying. She just said that to make you feel better.
Sheldon: Mom doesn't lie. Sure, she thinks the Earth was made in six days, but that's 'cause she's gullible, not a liar.

Ms. Fenley: You have perfect pitch.
Sheldon: Okay.
Ms. Fenley: Sweetheart, you should really pursue music.
Sheldon: No, thank you. Musicians take drugs. Is there a faculty restroom I could use?

Sheldon: Oh, I read that book. It's excellent.
Tam: Are you into rocketry?
Sheldon: I started with water propulsion, worked my way up to solid fuel, then went back to water after I set our garage on fire.

Sheldon: Well, good luck on your quest to find a friend.
Tam: You, too.
Sheldon: (Leaves the library, comes back a moment later) If you haven't found one yet, I have good news.

Pastor Jeff: Sometimes people say to me, "Pastor Jeff, how do you know there's a God?" And I say, "It's simple math. God either exists or he doesn't. So let's be cynical. Worst-case scenario, there's a 50-50 chance. And I like those odds.
Sheldon: That's wrong.

Sheldon: Oh, you better pull over.
Georgie: Oh, thank God.
Sheldon: Well, don't just sit there follow it.
Georgie: Why?
Sheldon: It's an ambulance It's going to the hospital.

Pastor Jeff: Yes, Sheldon.
Sheldon: You said he didn't create the sun until day four.
Pastor Jeff: Yeah.
Sheldon: So how could there be light the first three days?
Pastor Jeff: God is light.
Sheldon: So God's a photon?
Pastor Jeff: God's what made photons possible.
Sheldon: And what day did he do that?
Pastor Jeff: I would think day one.

Sheldon: I'm sorry I'm late. I have a note.
Ms. MacElroy: You poor thing, you had a medical emergency?
Sheldon: Yes, ma'am. I choked on a sausage. [laughter]
Boy: How big was it?
Sheldon: About yay big. [laughter]
Adult Sheldon: To this day, I still don't understand why they were laughing.

Adult Sheldon: As fate would have it, the comic I picked up was called X-Men. Young mutants with incredible powers who were feared and misunderstood by the entire world.
Sheldon: Hey, it's about me.

Sheldon: When the Aggies give up the ball on their own five-yard line, the opposing team has a 92% chance of scoring. When they punt from deep in their own territory, the other team still has a 77% chance of scoring. But since they convert on fourth down 50% of the time, the math says they should never punt again.

Sheldon: How come Mom's not taking me to school?
George: 'Cause once in a while, your dad wants to spend some time with you. My little Shel-man.
Sheldon: But Mom's car has a backseat. Statistically, I'm much safer there.