Sheldon: Excuse me, I was hoping to purchase some practical joke paraphernalia so that I may behave childishly.
Glenn: Rack in the corner.
Sheldon: Thank you. "If it's funny, it's a Bazinga." Interesting.

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]

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.

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.

Paige: You know, I read that adults who had a stunted childhood often become social misfits and weirdos.
Sheldon: You didn't read that, you're making it up like your goat story.
Paige: Psychology Magazine, February issue, 1988.
Sheldon: Well, um, that doesn't make it true.
Paige: Guess you'll find out when you're an adult.
Sheldon: I guess I will.
Adult Sheldon: Well, we know how this story ends. I grew up to become a well-adjusted and charming fellow. But at that moment in time, she had me worried.

Adult Sheldon: And that's how I became the madcap prankster all my friends know and love.

Dr. John Sturgis: I don't think I can do this, Connie.
Meemaw: Of course you can. We're just getting started.
Dr. John Sturgis: No, it's too much information. I can't process it.
Meemaw: It was just a yellow light.
Dr. John Sturgis: Not just the light. There were other cars. There's pedestrians. There was a guy on a bicycle.
Meemaw: So?
Dr. John Sturgis: That's just too many random elements. The- The- The stimuli are overwhelming.