Mary: I got to go to work. Keep an eye on her.
Sheldon: I will.
Mary: I was talking to your father, but actually, sure.

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.: [sings] ♪ The stars at night ♪ ♪ Are big and bright ♪ [claps four times] ♪ Deep in the heart of Texas ♪ ♪ The prairie sky ♪ ♪ Is wide and high ♪ [Georgie and Meemaw clap four times] ♪ Deep in the heart of Texas. ♪ Remember, it's always four claps. Never three, always four.
Meemaw: You know who claps three times? Yankees.
George Jr.: And as Texans, we always remember the Alamo.
Meemaw: Otherwise, we might as well just live in Oklahoma. Blech.

Sheldon: While Dad's gone, I'm the man of the house, and the man of the house has to enforce the rules.
Missy: The man of the house is about to get his teeth knocked out.
Sheldon: Puberty's made you mean.
Missy: I need to know what happened on my show.
Sheldon: And you'll find out when your privileges are restored.
Missy: I can't wait that long, each episode builds on the last. Imagine a Star Trek that ends with "to be continued," and you don't get to continue.
Sheldon: That would never happen, because I follow the rules.
Missy: You are this close to a purple nurple.
Sheldon: [covers nipples] You leave my nurples alone.

Sheldon: I know a way for you to watch whatever you want.
Missy: How?
Sheldon: Your imagination.
Missy: That's stupid.
Sheldon: Did you know there's a German folk song about it?
Missy: Don't.
Sheldon: [sings] ♪ My thoughts will not cater ♪ ♪ To duke or dictator ♪ ♪ No man can deny ♪ ♪ Die gedanken sind frei. ♪ [talks] Where are you going?
Missy: Mom said no music.
Sheldon: [hums melody]