Sheldon: I feel renewed. I'm ready to deal with any changes that come my way. [sees Penny] Your hair is different. You changed your hair. I can't take this. I'm out.

Mary Cooper: Thank you, God, for the food we are about to receive and for the nourishment of our bodies and bless the hands that prepared it. Amen.
Sheldon: Given that your hands prepared it, isn't that a little self-serving?
Mary Cooper: You start changing the words to the prayers, next thing you know, you're in a church with a guitar.

Penny: I'm a Sagittarius, which probably tells you way more than you need to know.
Sheldon: Yes, it tells us that you participate in the mass cultural delusion that the sun's apparent position relative to arbitrarily defined constellations at the time of your birth somehow affects your personality.
Penny: Participate in the what?

Sheldon: Who's ready to laugh? [Leonard groans] Okay. So Feynman, Einstein and Schrodinger walk into a bar. Feynman says, "It appears we're inside a joke." Einstein replies, "But only to an observer who saw us walk in simultaneously." To which Schrodinger says, "If someone's looking in the window, I'm leaving."
Leonard: [chuckles] That's actually funny.
Raj: You should send that to Jimmy Fallon.

Penny: Like, what'd you do last night?
Beverly Hofstadter: I had Cuban food at the home of a man with whom I shared unsatisfying intercourse.
Penny: Wow. Okay.
Beverly Hofstadter: And to anticipate your next questions, roasted pork and sideways missionary.
Penny: Sure. Sure. 'Cause you were full.

Sheldon: What is the best number? By the way, there's only one correct answer.
Raj: 5,318,008?
Sheldon: Wrong. The best number is 73. [short silence] You're probably wondering why.
Leonard & Howard: No, no, we're good.
Sheldon: 73 is the 21st prime number, its mirror 37 is the 12th and its mirror 21 is the product of multiplying, hang on to your hats, 7 and 3. Did I lie?
Leonard: We get it. 73 is the Chuck Norris of numbers.
Sheldon: Chuck Norris wishes. In binary, 73 is a palindrome, 1001001, which backwards is 1001001, exactly the same. All Chuck Norris gets you backwards is Sirron Kcuhc.
Raj: Just for the record, when you enter 5,318,008 in a calculator, upside down it spells boobies.

Raj: If you really want to challenge yourself, you could learn to speak Hindi.
Sheldon: Jab mein aat saal ka tha Maine seekha tha.
Raj: Could you say that in English? I actually, I never learned Hindi.

Penny: Helium.
Sheldon: Yes.
Penny: Yes.
Sheldon: Taylor Swift.
Penny: Yes. Pi.
Sheldon: Yes. Kardashian.
Penny: More specific.
Sheldon: Khloe?
Penny: Yes.
Sheldon: See, I remembered because if it looks like Kim it's Kim, if it looks kind of like Kim it's Kourtney, and if it looks nothing like Kim it's Khloe.

Howard: The man impersonating a bear would like you to know that, "Only you can prevent forest fires."
Raj: I don't get it.
Howard: You didn't have Smokey the Bear in India?
Raj: No. Was he anything like Munmun the Mongoose? He taught us not to play with cobras.
Howard: You had to be taught not to play with cobras?
Raj: You had to be taught not to burn down the forest?

Amy: If I may, I'd like to propose a toast. Um, thank you all for coming tonight. I know it's customary for the birthday boy to receive presents, but I feel like I got the greatest gift the day he was born.
Everybody: Aww.
Raj: Hear, hear.
Sheldon: Amy, that was lovely. You know, this is fun. Let's do more. Someone else say something wonderful about me.

Sheldon: [to Leonard] I don't know what your odds are in the world as a whole, but as far as the population of this car goes, you're a veritable mack daddy.

Raj: I don't like bugs, okay. They freak me out.
Sheldon: Interesting. You're afraid of insects and women. Ladybugs must render you catatonic.

Sheldon: Professor, can you identify our cricket?
Crawley: Of course I can. I can identify every insect and arachnid on the planet. Not that that's gonna keep me from having to move in with my daughter in Oxnard. And we're not talking Oxnard at the beach. No, we're talking Oxnard in the onion fields!

Leonard: Penny. We are made of particles that have existed since the moment the universe began. I like to think those atoms traveled fourteen billion years through time and space to create us, so that we could be together and make each other whole.

Mary: Let me straighten your tie.
Sheldon: No, no, no, it's all right. It's supposed to be a little asymmetrical. Apparently, a small flaw somehow improves it.
Mary: I can see that. Sometimes it's the imperfect stuff that makes things perfect.
Sheldon: Excuse me. *Sheldon rushes out of the room*
Mary: Case in point.