Mary: Tell me you don't miss their sweet little faces.
George: That's why we took pictures.
Mary: It's not the same as rocking 'em to sleep at night.
George: Until they wake you up at 3:00 a.m.
Mary: And smelling their little heads.
George: Really? That's the smell you remember?
Mary: Come on. It wasn't that bad.
George: It wasn't, but... we were younger then.
Mary: I'm not saying we should try for another one.
George: Great.
Mary: I'm just saying, if there was an accident... it might be a happy accident.
George: Mm-hmm. I guess it's in God's hands.
Mary: I guess it is.

Mary: So he's really good to graduate?
Principal Petersen: He sure is. I got to tell ya, usually when kids leave school after two years, it's not for college. It's for prison or pregnancy.
George: Well, between Georgie and Missy, we may hit the trifecta.
Mary: George!
George: Well, I'm not rooting for it. It's just a thing that could happen.

Georgie: A bill? Really?
George: Room and board, buddy.
Georgie: $50 a month for food?
George: The way you eat, I should've gone $50 a week.
Georgie: Laundry services?
George: Your poor mother has to touch your underwear.
Georgie: What's the $10 a month "peema" charge?
George: Oh, P-I-M-A, that's a "Pain in My Ass" tax. My way of getting compensated for you taking years off my life.

Georgie: You know what else is nice?
George: Hmm?
Georgie: I get to learn from all your parenting mistakes.
George: I'm starting to think letting you live this long was one of 'em.
Georgie: Like that. I'd never say something so awful to my kid. [George scoffs] Thanks, big guy.

Adult Sheldon: I always believed my extraordinary life would be chronicled in numerous biographies. I even used to make up my own titles. My favorites were: "From Texas to Success: the Sheldon Cooper Journey", and "Cooper for Kids", a pre-school introduction to quantum gravity in superstrings. The point is, I knew my formative years would be well-documented, which meant I needed to polish up some of my early academic credentials, especially East Texas Tech.

Sheldon: If W is the Kähler metric on the algebraic variety X, and the canonical bundle KX is trivial, then X is what?
Dr. John Sturgis: A Zariski space.
Sheldon: Wrong. [slaps Dr. Sturgis's hand with his pencil]
Dr. John Sturgis: Hey!
Dr. Linkletter: Obviously, it's an elliptic curve.
Sheldon: Wrong. [slaps Dr. Linkletter's hand with the pencil]
Dr. Linkletter: Hey!

Dr. John Sturgis: Why are you hitting us?
[flashback:]
Mei-Tung: Wrong.
Sheldon: Ow! Why'd you hit me?
Mei-Tung: Pain is the best teacher.
[present:]
Sheldon: I'm teaching you.
Dr. Linkletter: Well, it feels like you're hitting us.
Sheldon: Like you, I struggled with these concepts, but eventually, I mastered them, through hard work, resilience and a healthy dose of knuckle whacking.