Nathan: So, you can just type in whatever comic you're looking for, and the computer will tell you who has it?
Sheldon: Once enough people enter their inventories in the database, yes.
Nathan: That's really cool.
Sheldon: Would you say it's revolutionary?
Nathan: I would.
Sheldon: Will you?
Nathan: It's revolutionary.
Sheldon: Thanks.

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]

Sheldon: Missy and I broke a lot of rules the other night, and we've received no punishment.
George Sr.: [sighs] Buddy, it's been a rough week. We're just glad you're both safe.
Sheldon: But in the absence of a divine being, society's rules are what keeps a person's morality in check.
George Sr.: Well, there you go.
Sheldon: No, y-you're not following me. If actions have no repercussions, society breaks down, everything devolves into chaos.
George Sr.: You might be overthinking this.
Sheldon: I thought so, too. Then I thought about it, and I'm not.
George Sr.: Sheldon, you had one bad night. Just let it go.
Sheldon: But... I did something wrong and I got away with it. That's not okay.
George Sr.: Buddy...
Sheldon: Socrates maintained that the man who lies to himself has an enemy living within. He's not even a person. He's just a chaos of selfish desires wrapped in an animal hide.

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.

George Jr.: Were you mad at Mom for getting pregnant?
Meemaw: Oh, yeah.
George Jr.: Did you stop talking to her?
Meemaw: Hell no, I wanted her to hear how pissed off I was. But all that being mad at her just was a waste of time.
George Jr.: What made you come around?
Meemaw: I guess you showing up.
George Jr.: I do have a natural charm, don't I?
Meemaw: You did, and then you learned to talk.

Adult Sheldon: In the world of collecting, I'm what's known as a completist. For example, I own every gauge of model train from the mighty "G," to the tiny "T." Look at how cute it is, I just want to eat it up. However, the downside of being a completist is when something's missing, it's like an itch you can't scratch, even if you own a complete set of Justice League back scratchers... which I do. In this case that itch was the comic book issue Doom Patrol and Suicide Squad Special #1.

Sheldon: What do you mean, you sold it?
Missy: Somebody gave me money, and I gave them the comic book. That's kind of how things work here.