Sheldon: That boy has an exposed tattoo.
Mary: He does.
Sheldon: I wonder if he knows that's in violation of the dress code.

Adult Sheldon: I don't care how dimwitted you are, scientific principles have to make you smile. Of course, nobody I knew in East Texas in 1989 cared about Newtonian physics. The only Newtons they cared about were Wayne and Fig.

Billy Sparks: Hey, Sheldon!
Sheldon: Hello, Billy Sparks. Hello, Matilda Sparks.
Billy Sparks: I heard you're going to high school tomorrow.
Sheldon: I am. You're going to have to find someone else to torment on the playground.
Billy Sparks: "Torment"?
Sheldon: (sighs) It means to maliciously harass.
Billy Sparks: "Her ass"? (chuckles) That's funny.
Sheldon: Well, this was nice.
Billy Sparks: [holds chicken close to Sheldon's face] Hey, doofus! (squawks)
Sheldon: Mom!

Ms. Fenley: Do you know this sonata?
Sheldon: No.
Ms. Fenley: How long have you played the piano?
Sheldon: I don't play piano.

Sheldon: Dad, are you sad that you got fired?
George: Mostly angry. But, yeah, maybe a little sad.

George: I got fired, Sheldon. And I got a bad reputation.

Missy: Why can't we watch Duck Tales?
Sheldon: Because we don't learn anything.
Missy: It's TV! We aren't supposed to learn.

Sheldon: Good luck with your finger painting.
Missy: You're gonna get your ass kicked in high school.
Mary: [flicks Missy on the head] Hey!

Adult Sheldon: And when I figured out that trains allowed me to prove Newton's first law: "An object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force", I felt like Neil Armstrong on the moon, alone and happy.

Missy: Sheldon, if you don't get in here, I'm gonna lick your toothbrush!
Sheldon: Coming!
Adult Sheldon: That's my sister. And she's done it before.

Adult Sheldon: My mom was my Christian soldier. And for the record, they descended when I was 15.

Mary: Shelly, you don't really need a tie.
Sheldon: I have to find my tie. I have to find my tie.
Mary: Be right back.
Sheldon: Professor Proton wears a bow-tie!

Sheldon: Hey, he was about to power a clock with a potato.
George: Not possible.

Mary: George Junior, give me back that bow-tie right now!
Georgie: I didn't take it!
Mary: Don't you lie to me!
Georgie: I'm not lying!
Mary: We'll see about that.
Georgie: Stay out of my room!
Missy: She's gonna find your dirty magazines.
Georgie: Shut up!
Missy: You are not having a good day.

Sheldon: [emerging from the boys' room] Well, that was revolting.
Mary: [arriving at Sheldon's homeroom] All right. This is your homeroom. Do you want me to go in with you?
Sheldon: No. Although I could've used you in the restroom.