Adult Sheldon: Even while sleeping, my quest to save the princess continued, which was quite a departure from my usual dreams, such as determining the coolest prime number. Which, by the way, is 73.

Adult Sheldon: And that's how I became the madcap prankster all my friends know and love.

Adult Sheldon: Engineering has a rich and storied history, dating back to ancient times. Some consider it the single most important field of study... Okay, w-wha... no. Stop. I'm sorry. Howard, I can't do this.
Howard Wolowitz: You asked me to write you an introduction to engineering.
Adult Sheldon: Yes, and if I wanted a comedy routine, I'd have gone to Billy Crystal.
Howard Wolowitz: Just let me read it. [clears throat] Engineering has a rich and storied history dating back to ancient times. Some consider it the single most important field of study known to man, from the wheel to the International Space Station, which I went to.
Adult Sheldon: Honestly, this again?
Howard Wolowitz: Like we don't hear about your Nobel Prize all the time.
Adult Sheldon: It's not my fault people ask about it.
Howard Wolowitz: Because you're always wearing it! You have it on right now.
Adult Sheldon: Look how shiny it is.
Howard Wolowitz: [sighs] Just tell your story.

Professor Salzman: One should not even attempt to unify type-one und type-two...
Adult Sheldon: I wanted to give up and run away, but I had read enough comic books to know that heroes don't quit. Instead of running, I decided to stay and face the biggest challenge I've ever had: keeping my mouth shut.
Professor Salzman: Any thoughts on the compactification of the extra dimensions here?
[Sheldon goes to raise his hand along with Mei-Tung, but stops himself]
Adult Sheldon: Mmm.
Professor Salzman: Ja.
Mei-Tung: One must conserve the unbroken supercharges.
Professor Salzman: Und the spherical Hankel transform of this equation is... [Sheldon snaps his pencil]
Adult Sheldon: This turned out to be a pivotal moment in my life. By being open to people smarter than me, I grew as both a man and a scientist. Humble, brilliant... I really am the whole package.

[After Sheldon storms off with his upgraded computer:]
Jim: He gonna be okay?
George: Oh. Tonight, sure. Big picture? [shrugs]
Adult Sheldon: I've got a hot wife and a Nobel Prize. I turned out fine.

Adult Sheldon: Jane Goodall had to go to Africa to study apes. I just had to go to dinner.

Adult Sheldon: I've often been asked why I never learned to drive a car. This night is your answer.

Adult Sheldon: People often wonder why I chose to pursue a career in theoretical physics. I usually respond by saying I wanted to unravel the inner workings of the universe. But the real answer was I wanted to prove this nincompoop wrong.

Adult Sheldon: Whoever said the quickest way to a man's heart is through his stomach did not consider his tiny bladder.

Adult Sheldon: My new adult responsibilities began that night. Luckily, a cookbook is nothing more than a set of instructions. And if there's one thing I shine at, it's following instructions.

Adult Sheldon: In Texas, the Holy Trinity is God, football and barbeque, not necessarily in that order.

George: Damn it. I've had enough of this. Sheldon, get up.
Sheldon: What's the point?
George: We're going to Houston.
Sheldon: Really?
George: Yeah. You and me are gonna give those space monkeys a little talkin' to.
Adult Sheldon: I often found my father to be a strange and puzzling man, but at that moment, I never loved him more.

Adult Sheldon: Despite my explanation that I was embracing my inner Kirk, my mother had me make amends for all my misdeeds. Starting in the library, where I had to reshelve hundreds of books. Well, to be honest, that one was a hoot.

Adult Sheldon: Existing in a world of predators isn't easy, but we prey have developed several natural defenses to help us survive. There's playing dead, warning calls, camouflage, and, last but certainly not least, good old-fashioned running away. A little screaming never hurts either.

Adult Sheldon: In that moment, I was so angry with her, I almost opened the jar.