Principal Petersen: You ever play football?
Billy Sparks: No, sir.
Principal Petersen: Think about it. I will forge a birth certificate tomorrow.

Sheldon: You wanted to see me?
Principal Petersen: When don't I want to see you, Sheldon? Come in. I have something I'd like to give you. This is a key to the faculty restroom. No students allowed. One person at a time. And unlike the other restrooms, this one gets cleaned every night.
Sheldon: Thank you.
Principal Petersen: No, Sheldon. Thank you.
Sheldon: You're welcome.

[on the "Why Sheldon Cooper Should Go to College" tape:]
Principal Petersen: A student like Sheldon comes along... once in a lifetime. This school is not gonna be the same without him. But I know he's gonna do great things. And I'm honored to have been a small part of it.

George Sr.: Hey, Tom, you got a minute?
Principal Petersen: Pretty busy. Make it quick.
George Sr.: It turns out I don't need that raise.
Principal Petersen: What happened, you win the lottery?
George Sr.: No, no.
Principal Petersen: Aw, George, I am so sorry.
George Sr.: Well, what can you do?
Principal Petersen: Listen, I cleared your raise already, why don't you just keep the money.
George Sr.: Oh, no, I couldn't do that.
Principal Petersen: No. No, I mean it. It's yours.

Adult Sheldon: Like a virus, heartbreak can also spread. Once it does, it's hard to contain. In some cases you can try to reboot and start over. But it makes you appreciate those early days, when your hard drive was clean... and the world was full of possibility.

Meemaw: Well, let's get into it. What happened? If it's another woman, she's a tramp, and you're way prettier.
Brenda Sparks: No. Although sometimes I wish there was. Then I'd have someone to be mad at other than myself.
Meemaw: And here I thought this one was gonna be the sad sack.
Mary: Mom, that is enough.
Meemaw: Oh, there's my little killjoy. [both laughing]

Adult Sheldon: As long as humans have been on Earth, they've had to contend with viruses. And as long as I've been on Earth, I've come up with fun ways to avoid them.
[flashback:]
Dr. Linkletter: I've heard so much about you. [offers hand]
Sheldon: Apparently not how I feel about shaking hands.
Adult Sheldon: I wear personal protective equipment...
[flashback to Sheldon putting on mittens at the dinner table]
[flashback to Sheldon wearing an astronaut suit in his bubble:]
Mary: You come here right this instant.
Adult Sheldon: ...and I was social distancing before it was cool. But in the early '90s, a new type of virus became prevalent. One that no amount of hand-washing could stop. A computer virus.
Sheldon: Oh, no.
Adult Sheldon: But let's back up and begin this story in a simpler time, before an insidious infection had upended my life.