Penny: Uh, hey, guys, guys, you will really appreciate this, I read the best science joke on the Internet. Alicia, you won't get it, but it's right up their alley. Anyway, so, this physicist goes into an ice cream parlor every week and orders an ice cream sundae for himself, and then offers one to the empty stool sitting next to him. This goes on for a while until the owner finally asks him what he's doing. The man says, "Well, I'm a physicist, and quantum mechanics teaches us that it is possible for the matter above this stool to spontaneously turn into a beautiful woman who might accept my offer and fall in love with me." The owner then says, "Well, lots of single, beautiful women come in here every day, why don't you buy an ice cream for one of them, and they might fall in love with you?" And the physicist says, "Yeah, but what are the odds of that happening?"
Leonard: It's a little insulting, don't you think?
Penny: How would I know? I'm not even sure I get it.

Penny: Here you go, [to Leonard] quesadilla, [to Howard] salad, [to Raj] here's your pizza. And thanks to Sheldon's heated discussion with my manager, one barbecue bacon cheeseburger, barbecue sauce, bacon, and cheese on the side.
Sheldon: Thank you!
Penny: Go ahead. Eat it. I dare you!

Penny: [to Raj] Run to India.

Penny: [on the phone] No, mom. It's the same guy I've been going out with for the past two years. Yeah, the scientist. Well, it's complicated. He works with lasers and atomic magnets. No, I did not see it coming. No, we have not set a date. No, I am not pregnant. Yeah, this is a first for our family.

Raj: [to Amy] If you were having Sheldon's baby, would you really want him in the room?
Penny: Yeah, if he's in the room when they're making the baby, I'll give you $10.

Leonard: How was Nebraska?
Penny: Oh, better than North Dakota! [silence] I guess that joke's only funny in Nebraska.
Sheldon: From the data at hand you really can't draw that conclusion. All you can say with absolute certainty is that that joke is not funny here.
Penny: Boy, it's good to be back.

Sheldon: No, I don't want to go to sleep. You can't make me.
Penny: You're right, we can't.
Sheldon: Yeah, darn straight, you can't. Try to tell a grown man to go to sleep.
Penny: [sings] Soft kitty, warm kitty.
Leonard: [sings] Little ball of fur.
Sheldon: That's not gonna work.
Penny: Happy kitty, sleepy kitty.
Leonard & Penny: Purr, purr, purr.

Penny: All right, Sheldon, this craziness has gone on long enough. Please come home so I can cut your hair.
Sheldon: Penny, you're not trained. You're not licensed. Most importantly, you don't have access to my haircut records.
Penny: All right, honey, look, we've known each other for a long time now, right? I've taken you to Disneyland, I kicked a bully in the nuts for you, I sing you Soft Kitty when you're sick. You even saw me naked once.
Leonard: I'm sorry. Uh, what?
Penny: It was a long story. Anyway, Sheldon, I promise I know what I'm doing. Please let me cut your hair.

Penny: Sing Soft Kitty to me.
Sheldon: Soft Kitty is for when you’re sick. You're not sick.
Penny: Injured and drugged is a kind of sick.
Sheldon: [sings] Soft kitty, warm kitty, little ball of fur…
Penny: Wait, wait. Let's sing it as a round. I'll start. [sings] Soft kitty, warm kitty, little ball of fur… See that's where you come in. I'll start over. [sings] Soft kitty, warm kitty, little ball of fur… I've got all night, Sheldon. Soft kitty, warm kitty…
Both: [sing] ...little ball of fur, happy kitty, sleepy kitty, purr, purr, purr.

Penny: Can I tell you a secret?
Raj: Yeah.
Penny: I screwed up. Leonard's a great guy. Never should have broken up with him.

Leonard: What about if you went out with me?
Penny: Are you asking me out?
Leonard: Um, yes, I am, asking you out.
Penny: Wow.
Leonard: I was just going off your comment about the nice guy...
Penny: No, I know, I got that. Yeah, totally.
Leonard: ...thing and honestly, it's no big deal.
Penny: Yes.
Leonard: Yes what?
Penny: Yes, I will go out with you.
Leonard: Really?
Penny: Yeah. Why not, I mean, what do I have to lose?
Leonard: Yeah. That's the spirit.

Leonard: Okay, listen to me, this is just a minor setback.
Penny: No, it's not, okay? I've been out here for, like, ten years. I've nothing to show for it.
Leonard: Well, you have me.
Penny: You're right. I do have you. Mm. Let's get married.
Leonard: What?
Penny: Ooh. Leonard Hofstadter, will you marry me?
Leonard: Um…
Penny: Did you seriously just say um?
Leonard: Look, you know I love you but, but you're, you're drunk and sad and feeling lost.
Penny: Okay, so, so you don't want to marry me?
Leonard: That is not what I said.
Penny: No, forget it. I take it back. Offer's off the table.

Penny: See, that's the kind of passion I didn't think I had. But then I realized I'm passionate about you.
Leonard: Oh, my cute little tushy strikes again.
Penny: No, I'm serious. Look, I've always had these plans. I was gonna be in movies and live this glamorous life, and anything less than that just wasn't worth getting excited about.
Leonard: Those things can still happen.
Penny: Oh, obviously it's gonna happen. Yeah, a psychic at a bachelorette party told me so. Anyway, what I meant was, I shouldn't wait, you know? I've got you, I've got Sheldon, all these wonderful friends. My life is exciting right now.
Leonard: That's a big deal.
Penny: It is, isn't it?
Leonard: So, does that mean we get to do stuff like talk about cool shows or get dressed up in matching costumes and go to Comic-Con?
Penny: Leonard, I had an epiphany, not a stroke.

Penny: Leonard, you're back.
Leonard: Yeah, I just stopped by to say… [Penny grabs Leonard and kisses him] Yeah, so, hi!
Penny: Hi! [They stumble into her apartment while kissing]

Penny: Leonard, I don’t know what to tell you. It was just a hug.
Leonard: Glad we cleared that up.
Penny: Yeah.
Leonard: I guess I'll see you.
Penny: Okay, have a safe trip.
Leonard: Thank you. Bye.
Penny: Okay, bye. [closes door] It means I wish you weren't going.