Mary: What grade is she in?
Sheldon: Eleventh.
George Sr.: An older woman. Nice.
Sheldon: Most everybody's older than me. Why is that nice?

Mary: Let's say grace.
Sheldon: Hang on, safety first. [puts mittens on]
George Jr.: When are you gonna get over that?
Sheldon: I would think recent events would make you value protection.
Mary: Enough.

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.

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.

Adult Sheldon: As you can see, sometimes a person can be both incredibly intelligent and full of baloney.

Adult Sheldon: Anger is an ugly emotion. Unbridled rage even more so. And when it bubbled up inside me, I channeled it the only way I knew how. I cleaned the house like a man possessed.

Mary: You smoke marijuana?
Sheldon: Mom!
Libby: No, ma'am.
Tam: Just say no. [Mary shoots him an unimpressed look]