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.

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: My father didn't always get the credit he deserved. The advice he gave me actually worked out pretty well. Of course, I never told him.
George: Talked to Billy.
Missy: Why would you do that?
George: No, it was good.
Missy: Stay out of my life.
Adult Sheldon: He may not have been the world's greatest dad. But maybe we weren't the world's greatest kids.

Adult Sheldon: Ignoring things that irritate me isn't my strong suit. Obsessively fixating on them, now that's what gets me out of bed in the morning.

Adult Sheldon: Heidelberg is considered one of the most beautiful cities in Germany. Heidelberg Palace, the Karl Theodor Bridge, the Schloss Schwetzingen. But I couldn't care less. The only sights I wanted to see were the looks of awe on the faces of my fellow students as I demonstrated my intellectual superiority.
Sheldon: Cylinders that are smaller than ten to the minus-35 meters. [all laugh] What's happening?
Professor Salzman: You don't laugh at people saying stupid things in Texas?
Sheldon: You're darn tootin' we do. So who goofed? [laughter]
Professor Salzman: You did, dummkopf.
Sheldon: Dummkopf? You're calling me a dummy?
Professor Salzman: Class, who knows where the dummkopf went wrong? [hands go up] Mr. Ziegler.
Mr. Ziegler: He forgot to consider the Calabi-Yau manifold.
Professor Salzman: Thank you, Mr. Ziegler.
Sheldon: Wait, what's the Calabi-Yau manifold? [laughter]
Professor Salzman: Dummkopf.
Adult Sheldon: I was quickly learning not all Germans were the warm, fun-loving people I was led to believe.

Sheldon: And then they laughed at me for not knowing something that they knew. Who does that?
Mary: You do.
Sheldon: Well, this is no time for a teachable moment. Your child is hurting.
Mary: Sorry. [taps Sheldon's shoulder] There, there.
Sheldon: I guess that'll do. Now, how about a hot beverage?

Sheldon: Professor Salzman, I just wanted to let you know that I studied up and am now well-versed in the Calabi-Yau manifold.
Professor Salzman: Okay.
Sheldon: It was never part of the curriculum at East Texas Tech.
Professor Salzman: East Texas Tech? Sounds charming.
Sheldon: It's actually quite humid. Regardless, I'm ready to reassert myself as class leader.
Professor Salzman: Your classmates are from some of the most elite universities in the world. There is no East MIT.
Sheldon: Well, I would have gone to a better school, but I was 11, which you have to admit is pretty impressive.
Professor Salzman: Sheldon, at some point we ask of the piano-playing dog not, "Are you a dog?" but, "Are you any good at playing the piano?"
Sheldon: Excuse me?