Penny: So you have a song stuck in your head. It happens to everybody.
Sheldon: Well, I'm not everybody. I have an eidetic memory. I should be able to remember what song this is, but I can't. Something's wrong with me.
Penny: I told you if we were patient, he'd figure it out for himself.

Bernadette: So, you're really going out with Dave again?
Amy: Why not? He's actually a very nice guy.
Bernadette: But he spent an entire date talking about how much he loves Sheldon.
Amy: That's nothing Sheldon hasn't done before.

Sheldon: I remember the song! It's called "Darlin'" by the Beach Boys! Oh, thank goodness! I'm not crazy! I don't have to take a pigeon as my bride!
Leonard: There goes our shot at him living on the roof.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Sheldon: Amy, if you want to be my girlfriend again, I really want to be your boyfriend.
Amy: I really want that, too.
Sheldon: Good, because I love you.
Amy: I love you, too.
Dave: Kiss her, you brilliant fool!
(Sheldon kisses Amy)
Sheldon: Well, I'll let you get back to your date.

Penny: Well, she did soften your life, didn't she?
Sheldon: Yes! She's like the dryer sheets of my heart!

Sheldon: I know why the song was in my head.
Penny: Why?
Sheldon: It's about Amy.
Penny: Okay, look, I know Amy's like an old lady, but she's not old enough to have a song from the '60s written about her.

Sheldon: This is Leonard. He's your best friend in the world.
Leonard: All right, just stop. This is ridiculous.
Sheldon: Sometimes he gets cranky, but you can trust him with your life. And he does more things for you than I can even begin to list.
Leonard: Thank you.

Sheldon: Amy, there was a song I couldn't get out of my head. Eventually, I realized the song was about you, and like that earworm, I can't get you out of my heart. So, what I'm trying to say is, you're my heartworm. The metaphorical kind, not the poodle-killing kind.

Penny: I'll pay $1,000 to watch you cut footloose.
Sheldon: This is Penny. She is your friend. If she offers you food, it's safe to take it. You probably paid for it, anyway.

Penny: Oh, my God, he won't stop.
Leonard: How does he keep coming up with new ways to be annoying?
Penny: Nobody knows. That's why he's number one.

Leonard: I love you.
Penny: Who cares?

Sheldon: Dear Crazy Future Sheldon, you were driven mad by an earworm. Your mind, once your most trusted asset, is now a sack of parrots and monkeys. So I'm going to tell you everything you need to know. Uh, first, music is dangerous. The movie Footloose tried to warn us, but we wouldn't listen.

Amy: That's Sheldon.
Dave: You're kidding! How's my hair?

Sheldon: Sheldon Cooper's descent into madness day two. It's 2:25 a.m. and I feel the urge to urinate. My normal urination time is 7:10 a.m., but here I am, in the middle of the night, struggling to keep my mind sharp and my pajamas dry. It's only a matter of time before my tenuous grasp on reality fades. I suppose I should pee while I still know what a toilet is.