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?

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: Uh-oh.
Missy: What?
Sheldon: Listen to this. "French philosopher, mathematician and physicist, Blaise Pascal, argued a rational person should believe God exists because you have everything to gain if you're right, and nothing to lose if you're wrong."
Missy: Sounds right.

Sheldon: Do people know about this?
Meemaw: Sheldon, what's on a person's face is not always what's in their heart.
Sheldon: Well, this changes everything. How do you know who to trust?
Meemaw: You don't. That's what makes life interesting.

Adult Sheldon: I didn't realize until years later that my father was only asking questions about lightning and thunder to cheer me up. In fact, he would often pretend to be dumb just to make me feel better.

George Jr.: What are you doing?
George Sr.: Separating the whites from the colors.
George Jr.: Whoa, that's racist.

Sheldon: Mom.
Mary: [wakes up] What is it, Sheldon?
Sheldon: I know you had some questions about Star Trek, so I've compiled a detailed guide outlining all the shows, characters, and how they fit in a timeline.
Mary: Can we do this later? I've got a headache.
Sheldon: Unfortunately not. If we don't do it now, you'll be completely lost when we watch The Animated Series this afternoon.
Mary: Just 20 more minutes.
Sheldon: Mom, this is almost a hundred pages. We have to get started. In the 23rd century, alien races from around the galaxy have come together to form the United Federation of Planets, which is... open your eyes... Headquartered in San Francisco.

George Sr.: What the hell, Brenda?
Brenda Sparks: What the hell, what?
George Sr.: Your friends all know about your "secret boyfriend"?
Brenda Sparks: You think that's you?
George Sr.: Well... it's not?
Brenda Sparks: No, George.
George Sr.: Well, who is it?
Brenda Sparks: I didn't tell them. I'm not gonna tell you.
George Sr.: Okay.
Brenda Sparks: Oh, God. Are you upset that there might be another guy in the picture?
George Sr.: No.
Brenda Sparks: Good. Go home to your wife.
George Sr.: I will.
Brenda Sparks: Okay. [George exits] [chickens clucking] Shut up.

Mary: I did what you said and I made some new friends.
George Sr.: Well, good for you. Who?
Mary: Brenda, Jill, and, ooh, either Helen or Ellen, but I missed my window to make sure. [laughs]
George Sr.: Sounds fun.
Mary: It was. Oh... [gasps] and get this, I got dirt.
George Sr.: Ooh, what kind of dirt?
Mary: Brenda has a secret man that she is hiding from everybody. [chuckles]
George Sr.: Really?
Mary: And he might be married.
George Sr.: [chuckling] Really? Well, who do you think it is?
Mary: Oh, I don't know, but me and the gals are gonna find out. [George chuckles]