Adult Sheldon: My meemaw didn't understand. When I was feeling anxious, it was rules and structure that I found soothing... Not to mention the relaxing melody of the Star Trek theme song.
Sheldon: [humming Star Trek theme]
Meemaw: Stop that.
Sheldon: As soon as I'm soothed. [resumes humming Star Trek theme]

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: Sheldon, faith means believing in something you can't know for sure is real. And right now, I am struggling with that.
Sheldon: So you don't believe in God anymore?
Mary: That isn't something for you to worry about. I need to figure this out myself.
Sheldon: Can I help? Maybe I could provide a fresh perspective.
Mary: I don't think so, baby.
Sheldon: Did you know that if gravity were slightly more powerful, the universe would collapse into a ball?
Mary: I did not.
Sheldon: Also, if gravity were slightly less powerful, the universe would fly apart and there would be no stars or planets.
Mary: Where you going with this, Sheldon?
Sheldon: It's just that gravity is precisely as strong as it needs to be. And if the ratio of the electromagnetic force to the strong force wasn't one percent, life wouldn't exist. What are the odds that would happen all by itself?
Mary: Why are you trying to convince me to believe in God? You don't believe in God.
Sheldon: I don't, but the precision of the universe at least makes it logical to conclude there's a creator.
Mary: Baby, I appreciate what you're trying to do, but logic is here. And my problem is here.
Sheldon: Well, there are 5 billion people on this planet and you're the perfect mom for me. What are the odds of that?

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.

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.

Meemaw: Hey. Good news. Your dad's doing okay and should be home in a couple of days.
Missy: Thank God.
Sheldon: Thank modern medicine.

Sheldon: I'm having a moral quandary, and I could really use your help.
Meemaw: Oh, moral quandaries. I hate those. Shoot.
Sheldon: You're the least moral person I know... How do you live with yourself?
Meemaw: I'm about to shut this door in your face.
Sheldon: See? Other people would be kind to a child in need. That's why I came to you.
Meemaw: Okay, fine. What do you want?
Sheldon: I'm confused as to how to go about my business after misbehaving and not being punished.
Meemaw: And where do I come in?
Sheldon: You tell lies, you gamble, you have quite the potty mouth, and yet you never seem to pay a price for any of it.
Meemaw: Well, when you're cute like me, rules are just a little different.
Sheldon: Hmm. That would also explain the endless parade of romantic partners. [Meemaw slams the door] Are you leaving because you have a man in there?
Meemaw: No!
Sheldon: Hmm. Although she would lie about it, so who knows?