Mary: I'm home.
Sheldon: Would you care to explain this letter, which I didn't read but legally know the contents of?

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.

Mary: So, George is mad at me, and Sheldon is mad at me, and... honestly, I'm mad at me, too.
Brenda Sparks: Will you please give yourself a break? All that you do for that family, I am surprised you didn't crack years ago.
Mary: How do you handle it all?
Brenda Sparks: I'm sitting in a chicken coop drinking a wine cooler at 11:00 a.m.... clearly, I don't.

[on the "Why Sheldon Cooper Should Go to College" tape:]
Ms. Ingram: Honestly... teaching Sheldon is the hardest thing I've ever had to do. And I don't say that because he can be a pain. I say that because he's so intelligent, I had to study every night just to keep up. I'm gonna miss him.

Missy: Interesting.
Sheldon: What does it say? No, don't tell me. Okay, tell me. No, don't!
Missy: Sheldon, if I tell you but you never look at it, then you didn't break the law, right?
[later:]
Janice: [answers phone] Law offices of Morris, Morris & Yorn. Janice speaking.
Sheldon: [on the phone] Hello. I'd like to speak to either Morris, Morris or Yorn.
Janice: May I ask what it is in regard to?
Sheldon: Well, I was slicing a hot dog...