[Sheldon is holding his nose and puffing his cheeks out:]
Mary: What're you doing?
Sheldon: Trying to get my ears to pop.
Mary: Want a piece of gum?
Sheldon: Is it cinnamon gum?
Mary: Yeah.
Sheldon: I have enough problems. [baby cries] Oh, you've got to be kidding me.

Sheldon: I started working on this presentation to address specific ethical dilemmas. The laws of robotics, whether torture can be justified, and cloning people for fun and spare parts. But I realized before resolving any of these moral quandaries, the real decision is who gets to decide. Do we put it up for a vote? Does everyone get to decide for themselves? Should it be by committee? Is that committee elected or appointed? You see where I'm going? You probably don't. For the smartest decision, we need the smartest person. Ladies and gentlemen, in the field of scientific ethics, we can't rely on democracy or plutocracy. We need an autocracy, or to be more precise, a "Sheldocracy." [slams fist] [military march plays]
Dr. John Sturgis: Um, I don't think this was the assignment.
Sheldon: Sorry, Dr. Sturgis, I pick the assignments now. Everybody, for next class, I want 500 words on what you can do to further the Sheldocracy. Punishment for typos will be severe.
Dr. John Sturgis: Class dismissed.
Sheldon: Hey, that's my line.
Dr. John Sturgis: No, it isn't.
Sheldon: Why don't you see me after class. Class dismissed.

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: You understand that some people are going to be intimidated by you, because of how smart you are?
Sheldon: Or maybe they'll recognize my intellect and make me their leader.

Mary: Are you ready for your surprise?
George: I sure am.
Mary: Okay. [German accent] Hello, you handsome American boy toy. I am Helga. Do you like what you see?
George: [German accent] Yeah. Yeah. Yeah. Yeah. [both laugh]
[Sheldon unlocks the front door and walks into the house]
Sheldon: Hello?
Mary: [o.s.] Are you sure your wife won't come home?
George: [o.s.] [laughs] I'm sure.
[Sheldon knocks on his parents' bedroom door and then opens it]
George: [o.s.] Yeah, yeah. [Mary laughs] Oh, Helga.
Adult Sheldon: I never talked to my father about what I saw that day, but, from then on, I added extra knocks so people could get their pants on.

Sheldon: Mark my words, string theory is going to be the next big thing.
Mary: What does it do?
Sheldon: It explains the fundamental forces of the universe. How everything works, where everything came from.
Mary: I know where it all came from. [points to the heavens]
Sheldon: Mother, we're in the sky. Why are you pointing up?

Pilot: [v.o.] Sorry for the delay. We hope to be wheels up in about 20 minutes.
Sheldon: That's what he said 20 minutes ago.
Mary: Nothing we can do.
Sheldon: If we don't take off soon, we'll miss our connecting flight to Houston.
Mary: It's out of our hands. I'd tell you whose hands it's in, but you don't like that.