Adult Sheldon: As long as I can remember, unlocking the mechanisms that govern the physical universe was my greatest passion.
Mary: Whatcha workin' on?
Sheldon: Dungeons & Dragons.
Adult Sheldon: Hey, even Hawking took a roll through the park once in a while.
Sheldon: I'm working on a new campaign to play with Tam and Billy.
Mary: You know how I feel about that game.
Sheldon: I'm aware, which is why the most wicked thing in it is my sense of humor. [doorbell rings]
Mary: [sighs] I still don't like it. But you are playing with other kids, so I'll take it as a win.
Adult Sheldon: Not just playing with other kids, controlling every aspect of their destiny as their Dungeon Master overlord. I didn't believe in God but I sure loved acting like one.

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.

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?

George Jr.: Just out of curiosity, when exactly are you and Mom leaving, and when exactly are y'all coming back?
George Sr.: You're not bringing your girlfriend here.
George Jr.: Excuse me for taking an interest in your life.
George Sr.: Besides, your grandma'll be here the whole time.
George Jr.: Never mind. Wait. So her house'll be empty?
George Sr.: Look, I used to be your age, but can you try thinking with your brain for once?
George Jr.: If you used to be my age, I think you know the answer to that.

Mary: So you've stayed at this hotel before?
George Sr.: Oh, yeah. It's nice. They got an indoor pool and a killer breakfast buffet. There's even a real nice gym we'll walk right past on the way to the breakfast buffet.

Darlene: Ooh, this camper is so cool.
Mary: We borrowed it from my mom's boyfriend.
George Sr.: Yeah, you might not want to poke around too much. You find my mother-in-law's bra, I'm driving into a brick wall.