Mary: Here's a question for you. Do you ever see or hear things that other people can't?
Sheldon: Oh, all the time. Right now, the car antenna is vibrating at the same frequency as the pistons in the motor. It's quite irritating, but you know me I don't complain.
Mary: I meant more like things that aren't actually there.
Sheldon: Ah, isn't that the fundamental question of modern metaphysics? What is actually there? This is fun. Missy should ride with Dad more often.

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: Too bad. We are going.
Sheldon: Class is starting tomorrow. I'm not going anywhere.
Mary: Sheldon, do not argue with me. You are going home.
Sheldon: Mom, the people of Germany are obsessed with rules and devoid of humor. I am home.

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.

Mary: I was just letting you know that if you were having any problems you could come to me with them.
Sheldon: You think I have mental problems?
Mary: Well, not problems. I'm just worried about your future, and when I see you moving subatomic particles around in the air, that makes-
Sheldon: Subatomic particles are real! You talk to an invisible man in the sky who grants wishes. If anyone's mental, it's you.

Sheldon: Why aren't you also driving Missy to school?
Mary: I thought it might be nice for us to chat.
Sheldon: About Missy? She is a bit much, isn't she?

Ms. Hutchins: We have a few books on mental illness you might find helpful. This one's a good place to start.
Sheldon: Have you read it?
Ms. Hutchins: Read it, lived it, made the mistake of talking about it on a date. [as Sheldon leaves] Sure. Walk away. They all do.