Adult Sheldon: My dad was right. I had to take charge. And after 20 more minutes of pouting, that's exactly what I did. But despite my best efforts, I was still no closer to figuring it out. I was going to have to see my work be torn to pieces one more time. [Sheldon's pages blow in the wind]
Sheldon: Of course.
Adult Sheldon: I'd been so focused on mathematical perfection that I hadn't taken into account real-world elements. Wind can trigger vibrations. If these vibrations occur at a system's resonant frequency, then oscillation generates excitation and a bridge can lose its structural integrity.
Sheldon: Okay, I'm a genius again.
Adult Sheldon: I couldn't wait to hand in my paper and see the proud look on Professor Boucher's... [Sheldon is unable to open the locked door]
Sheldon: No! I figured it out! [Boucher points to his watch] It's wind! It's wind! I hate engineering.

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.

George Sr.: What are you doing?
Missy: Watching Sheldon struggle with homework. It's so great.

Adult Sheldon: Engineering has a rich and storied history, dating back to ancient times. Some consider it the single most important field of study... Okay, w-wha... no. Stop. I'm sorry. Howard, I can't do this.
Howard Wolowitz: You asked me to write you an introduction to engineering.
Adult Sheldon: Yes, and if I wanted a comedy routine, I'd have gone to Billy Crystal.
Howard Wolowitz: Just let me read it. [clears throat] Engineering has a rich and storied history dating back to ancient times. Some consider it the single most important field of study known to man, from the wheel to the International Space Station, which I went to.
Adult Sheldon: Honestly, this again?
Howard Wolowitz: Like we don't hear about your Nobel Prize all the time.
Adult Sheldon: It's not my fault people ask about it.
Howard Wolowitz: Because you're always wearing it! You have it on right now.
Adult Sheldon: Look how shiny it is.
Howard Wolowitz: [sighs] Just tell your story.

June: I got to admit, I'm a little jealous.
Meemaw: Of what?
June: You.
Meemaw: Why?
June: You have the Dale I never got. I spent a lot of time polishing that turd, and you get all the benefits.
Meemaw: Hey, I put my time in on that, too.
June: Not as much as me.
Meemaw: When I met him, he was a mess.
June: [laughs] You should've seen where I started.
Meemaw: Well, I think we can both agree, he is one lucky turd.
June: Amen, sister.