Sheldon: [on the phone] Hello. Yes, you can help me, Dorothy Fitzpatrick. I'm interested in taking out a second mortgage. I'm nine years old. Why do you ask? That's called age discrimination, Dorothy, but I'm willing to let it slide. I'm glad you find me cute, but I'm deadly serious. I need funds to buy a computer. No, the house isn't in my name. I'm nine. We've established this. I do prepare the taxes for my parents, and if we tighten our belts, we'll have sufficient equity for the loan.

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.

Principal Petersen: Our next young speaker needs no introduction, but that didn't stop him from writing one and making me read it. [laughter] "Fun fact." [audience groans, murmurs] I hear you. "The word 'valedictorian' is from the Latin 'valedicere,' meaning 'to say farewell.' It is primarily used in the United States, Canada, the Philippines and Armenia." Maybe that fact's more fun in Armenia. Please welcome your valedictorian, Sheldon Cooper.
Mary: Yay, Shelly!
Sheldon: Hello. I'm not very comfortable speaking in front of crowds. But there's a technique to reduce stage fright by focusing on one person in the audience and delivering your speech just to them. That's what I'll be doing today. If it weren't for this person, I wouldn't be here right now. They've taught me a lot, and it's by their example that I found the courage to move forward into this new and exciting chapter of my life. Missy... ...this is for you. Change can be scary, but I know we're going to be fine... ...because like you said, "It's okay to be scared. We just have to do it anyway." So if any of my fellow graduates are nervous about the future, know that you're not alone. I suggest you all try to be as brave as my twin sister. That's my plan. Missy, I wish I could give you advice about middle school, but I was so smart, I skipped it. If you make it to high school, we'll talk. Thank you. [applause]

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.

Adult Sheldon: People often wonder why I chose to pursue a career in theoretical physics. I usually respond by saying I wanted to unravel the inner workings of the universe. But the real answer was I wanted to prove this nincompoop wrong.

George Sr.: Damn it. I've had enough of this. Sheldon, get up.
Sheldon: What's the point?
George Sr.: We're going to Houston.
Sheldon: Really?
George Sr.: Yeah. You and me are gonna give those space monkeys a little talkin' to.
Adult Sheldon: I often found my father to be a strange and puzzling man, but at that moment, I never loved him more.

Dr. Hodges: Now, what I thought would be fun to talk about today is what NASA's planning on doing beyond the Space Shuttle. Things like the first manned mission to Mars. Uh, yeah?
George Jr.: Did you see the movie Aliens?
Dr. Hodges: I did.
George Jr.: Did you think it was cool?
Dr. Hodges: Uh, sure, I enjoyed it.
George Jr.: Me, too.
Dr. Hodges: Football player, right?
George Jr.: Yes, sir.