Dr. John Sturgis: Why are you hitting us?
[flashback:]
Mei-Tung: Wrong.
Sheldon: Ow! Why'd you hit me?
Mei-Tung: Pain is the best teacher.
[present:]
Sheldon: I'm teaching you.
Dr. Linkletter: Well, it feels like you're hitting us.
Sheldon: Like you, I struggled with these concepts, but eventually, I mastered them, through hard work, resilience and a healthy dose of knuckle whacking.

Sheldon: I started working on this presentation to address specific ethical dilemmas. The laws of robotics, whether torture can be justified, and cloning people for fun and spare parts. But I realized before resolving any of these moral quandaries, the real decision is who gets to decide. Do we put it up for a vote? Does everyone get to decide for themselves? Should it be by committee? Is that committee elected or appointed? You see where I'm going? You probably don't. For the smartest decision, we need the smartest person. Ladies and gentlemen, in the field of scientific ethics, we can't rely on democracy or plutocracy. We need an autocracy, or to be more precise, a "Sheldocracy." [slams fist] [military march plays]
Dr. John Sturgis: Um, I don't think this was the assignment.
Sheldon: Sorry, Dr. Sturgis, I pick the assignments now. Everybody, for next class, I want 500 words on what you can do to further the Sheldocracy. Punishment for typos will be severe.
Dr. John Sturgis: Class dismissed.
Sheldon: Hey, that's my line.
Dr. John Sturgis: No, it isn't.
Sheldon: Why don't you see me after class. Class dismissed.

Principal Petersen: Our next young speaker needs no introduction, but that didn't stop him from writing one and making me read it. [laughter] "Fun fact." [audience groans, murmurs] I hear you. "The word 'valedictorian' is from the Latin 'valedicere,' meaning 'to say farewell.' It is primarily used in the United States, Canada, the Philippines and Armenia." Maybe that fact's more fun in Armenia. Please welcome your valedictorian, Sheldon Cooper.
Mary: Yay, Shelly!
Sheldon: Hello. I'm not very comfortable speaking in front of crowds. But there's a technique to reduce stage fright by focusing on one person in the audience and delivering your speech just to them. That's what I'll be doing today. If it weren't for this person, I wouldn't be here right now. They've taught me a lot, and it's by their example that I found the courage to move forward into this new and exciting chapter of my life. Missy... ...this is for you. Change can be scary, but I know we're going to be fine... ...because like you said, "It's okay to be scared. We just have to do it anyway." So if any of my fellow graduates are nervous about the future, know that you're not alone. I suggest you all try to be as brave as my twin sister. That's my plan. Missy, I wish I could give you advice about middle school, but I was so smart, I skipped it. If you make it to high school, we'll talk. Thank you. [applause]

Mary: You understand that some people are going to be intimidated by you, because of how smart you are?
Sheldon: Or maybe they'll recognize my intellect and make me their leader.

Adult Sheldon: I always believed my extraordinary life would be chronicled in numerous biographies. I even used to make up my own titles. My favorites were: "From Texas to Success: the Sheldon Cooper Journey", and "Cooper for Kids", a pre-school introduction to quantum gravity in superstrings. The point is, I knew my formative years would be well-documented, which meant I needed to polish up some of my early academic credentials, especially East Texas Tech.

Sheldon: If W is the Kähler metric on the algebraic variety X, and the canonical bundle KX is trivial, then X is what?
Dr. John Sturgis: A Zariski space.
Sheldon: Wrong. [slaps Dr. Sturgis's hand with his pencil]
Dr. John Sturgis: Hey!
Dr. Linkletter: Obviously, it's an elliptic curve.
Sheldon: Wrong. [slaps Dr. Linkletter's hand with the pencil]
Dr. Linkletter: Hey!

Dr. Linkletter: Son, we are accomplished scientists. We won't be treated like this.
Sheldon: Very well.
[flashback:]
Professor Salzman: Class, who knows where the dummkopf went wrong?
Sheldon: Dummkopf? You're calling me a dummy?
[present:]
Sheldon: There's also public humiliation. That was quite effective. Are you old dummkopfs ready to learn, or is it past your bedtime?
Dr. John Sturgis: Oh, I'm good till at least 7:30.