Adult Sheldon: I've often contemplated what might have happened if my father hadn't stuck up for me that day. Would I have gone on to become a world-class theoretical physicist, or just your average Joe Sixpack theoretical physicist?

Adult Sheldon: Then back home, he applied the spice rub with such erotic tenderness, it made my mother a little jealous.

Adult Sheldon: Not all science is created equal. There's physics, the undisputed king of science. There's chemistry. It's no physics, but it's not a bad way to pass a rainy afternoon. And then there's biology, the squishiest of the sciences.

Sheldon: Mom, Dad, I've made a decision.
George: [turns TV off] All right.
Sheldon: I'm going to MIT.
Adult Sheldon: I know what you're thinking. Wait for it.
Sheldon: I'm so excited to visit MIT.
George: Me, too. Proud of you, son.
Sheldon: Thank you, Dad.
[As Sheldon and George step out of Boston Logan International Airport, the wind is howling and there's snow built up on the ground]
Sheldon: Caltech?
George: Caltech.
Adult Sheldon: Told you.

Mary: Say "Nana." Nana. Na-na.
George: Ain't she a little young for that, Mare?
Adult Sheldon: For the record, I said my first word at four months. It was "hypotenuse."

[future:]
Amy Farrah Fowler: I would love to dissect your brain to see which part is missing.
Adult Sheldon: Or you'll find an all-new structure no one's ever seen before, an evolutionary leap forward.
Amy Farrah Fowler: Don't push me, I have a bone saw. [exits]
Adult Sheldon: All these years, and the passion is still there.

[future:]
Amy Farrah Fowler: Get dressed.
Adult Sheldon: But I'm busy. I'm writing about my last few days in Texas before going to Caltech. It's very emotional.
Amy Farrah Fowler: I can see that. Hit the showers.
Adult Sheldon: [stammers] I'm right in the middle. Mom's going off the rails, I'm holding the whole family together. This is riveting stuff.
Amy Farrah Fowler: Well, I am leaving in an hour and you are coming with me. [Sheldon coughs] Stop it. You are not sick.
Adult Sheldon: You're not that kind of doctor. You don't know.

[future:]
Amy Farrah Fowler: Sheldon, I know you're not a fan of sports, but it would mean so much to Leonard to have his father in the stands supporting him.
Adult Sheldon: He knows I love him, despite his foolish and embarrassing hobby.
Amy Farrah Fowler: Sheldon, it is not a hobby...
Adult Sheldon: End of discussion.
Amy Farrah Fowler: Do not tell...
Adult Sheldon: End!
Amy Farrah Fowler: March your cute behind upstairs and get in that shower.
Adult Sheldon: Fine. But that doesn't mean I'm going. It means I value good hygiene.

Adult Sheldon: My father took pride in saying that he ran our house like a tight ship. The ship got a lot looser when my meemaw came over to babysit.

Adult Sheldon: Despite what it looks like, I didn't pray to God that night. I prayed to Blaise Pascal. My thinking was, if he was right about the existence of God, then he could pass along my request for my dad to get better. If he was wrong - well in this moment, I needed him to be right.

Georgie: Looks like rain.
Adult Sheldon: My brother, on the other hand, didn't have to pretend.

Adult Sheldon: In any ecosystem, you'll find a delicate balance between predator and prey.
Some well-known predators include Panthera leo, Ursus arctos, and star of the 1987 film Predator, Predator. Now, examples of prey include Oryctolagus cuniculus, Gallus gallus domesticus, and weighing in at 58 pounds soaking wet, Diminutive homo novus Curiously, a close relative of Gallus gallus domesticus.

Adult Sheldon: At that moment, I felt a subtle heat rising through my body. I was used to being humiliated by my siblings on a daily basis, but from my mother? This was new territory.

Adult Sheldon: To say this first day was challenging would be an understatement. To say the rest of the week got better from there would be the kind of lie that sets pants on fire.

Adult Sheldon: : Vulcans use a technique called Kolinahr to suppress their emotions.
Mary: [OFF-SCREEN] Sheldon, they're here!
Adult Sheldon: Obviously, I wasn't a Vulcan. So I did the next best thing: took my feelings and shoved them down so far they may have been lost forever.