Leonard: We're going to Long Beach?
Sheldon: No, of course not. There's no Cousin Leo; there's no intervention. Focus, Leonard.
Leonard: Oh, come on.
Sheldon: We just leave the house on Friday night, and we return in the wee hours, emotionally wrung out from the work of convincing Leo to go back into rehab.
Leonard: So, he goes back into rehab?
Sheldon: Yes, but he can relapse if Penny ever invites us to hear her sing again

Every family in America has a relative holed up in a garage somewhere huffing paint thinner

Penny

Leonard: Sheldon, are you worried about your safety?
Sheldon: No, I imagine if you were going to kill me, you'd have done it a long time ago.
Leonard: That's very true

Leonard: Penny, say hello to Leo.
Penny: Hi, Leo. How are you feeling?
"Leo": Have you ever woken up in a flea-bag motel, covered in your own vomit, next to a transsexual prostitute?
Penny: No.
"Leo": Then don't ask me how I'm feeling.

Leonard: How long is [Leo] going to stay here?
Sheldon: He's a homeless drug addict, Leonard. Where's he going to go? Boy, you have a lot to learn about lying

Sheldon [knocking on Penny's door]: Penny, Penny, Penny...
[Penny opens the door]
Sheldon: Good morning.
Penny: Do you have any idea what time it is?
Sheldon: Of course I do, my watch is linked to the atomic clock in Boulder, Colorado. It's accurate to one-tenth of a second, but as I'm saying this it occurs to me once again your question may have been rhetorical

Sheldon: I'm uncomfortable having been included in your lie to Penny.
Leonard: What was I supposed to say?
Sheldon: You could have told her the truth.
Leonard: That would have hurt her feelings.
Sheldon: Is that a relevant factor?
Leonard: Yes.
Sheldon: Then I suppose you could have agreed to go.
Leonard: And what would I have said afterwards?
Sheldon: I would suggest something to the effect of, 'singing is neither an appropriate vocation nor avocation for you, and if you disagree I'd recommend you have a CAT scan to look for a tumor pressing on the cognitive processing centers of your brain

The Big Bang Theory Season 1 Episode 10 Quotes

Sheldon [knocking on Penny's door]: Penny, Penny, Penny...
[Penny opens the door]
Sheldon: Good morning.
Penny: Do you have any idea what time it is?
Sheldon: Of course I do, my watch is linked to the atomic clock in Boulder, Colorado. It's accurate to one-tenth of a second, but as I'm saying this it occurs to me once again your question may have been rhetorical

Sheldon: I'm uncomfortable having been included in your lie to Penny.
Leonard: What was I supposed to say?
Sheldon: You could have told her the truth.
Leonard: That would have hurt her feelings.
Sheldon: Is that a relevant factor?
Leonard: Yes.
Sheldon: Then I suppose you could have agreed to go.
Leonard: And what would I have said afterwards?
Sheldon: I would suggest something to the effect of, 'singing is neither an appropriate vocation nor avocation for you, and if you disagree I'd recommend you have a CAT scan to look for a tumor pressing on the cognitive processing centers of your brain