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.

Adult Sheldon: I never did get to see a launch in person, but that was the best trip I ever had. I wish I had told my father while he was alive.

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.

Adult Sheldon: Visiting Tam's house for the first time was an emotional roller coaster.
For example, it's traditional in Vietnamese homes to have gruesome religious iconography near the entrance. I did not like that.
However, it's also customary to not wear shoes around the house for sanitary reasons. I did like that.
Interestingly, one of the main ingredients in Vietnamese cooking is an extremely pungent condiment known as fish sauce. I did not like that.
But before every meal, it's common for everyone to wash their hands and face. I did like that.
Forks are not customary in a Vietnamese household. I did not like that.
And instead of napkins, there was one towel for everyone to share at the table. Seriously, what are they thinking?

Adult Sheldon: My sister encouraged me to embrace adolescence as a journey of scientific discovery. I stood before a whole new teenage world of music, slang words and even clothing styles. [Sheldon removes a red Flash t-shirt] Pretty groovy, huh?
[Sheldon stands in front of his bedroom mirror wearing the red Flash t-shirt over a blue undershirt]
Sheldon: Wow, I might look too cool.

Mary: How was your day?
George Sr.: Awful.
Mary: Oh. Well... I have good news.
George Sr.: I could use it.
Mary: I got a job at the bowling alley.
George Sr.: [gulps] Working with Brenda?
Mary: Every day. [phone rings]
George Sr.: That is... really... really good news.
Mary: Mm-hmm.

Sheldon: Maybe we should go to the emergency room.
Missy: It's just a pimple. Pop it.
Sheldon: No.
Missy: I'll do it. I like when it hits the mirror. Now hold still.
[fantasy: A.V. and Pus are now standing, with no chair or stool in sight:]
A.V.: It seems we've reached the end of our time with Sheldon. [Pus is holding two suitcases] But it's never truly goodbye. We'll be back in moments of stress. Like a big test. Or my personal favorite, school picture day... [they disappear in an explosion of yellow pus, leaving the two suitcases]