Penny: He can take care of himself. We went over Stranger Danger and gave him that whistle.

Leonard: It's dark out and he's alone. I don't like it. Let's go get him.
Penny: It's sweet how you look out for him. You're a good guy.
Leonard: It's not just that. My mother would kill me if I let something happen to him.

Stuart: I was wondering if I could crash at your place for a few nights.
Raj: Sure, of course. Oh, actually Emily was going to spend the night.
Stuart: You slept with her? Nice.
Raj: I can't take all the credit. She let me do it to her.

Leonard: Seriously? You don't even have a change of clothes or a toothbrush.
Sheldon: My plan is to stop at malls and buy what I need. It's called living off the land.

Penny: He'll be okay. You taught him well, Padawan.
Sheldon: Good Lord. Padawan is the student, not the teacher.
Penny: Seriously, let him go.

Bernadette: She's just so impossible, they keep quitting.
Sheldon: So who's watching her now?
Howard: A bowl full of M&Ms with a few Ambien tossed in.

Sheldon: You tracked my phone?
Leonard: Yeah.
Sheldon: Boy, you chase one balloon for three miles.
Penny: We were worried about you.
Sheldon: Don't be melodramatic. I'm just getting on a train and leaving for ever.

Leonard: You know he can't take a trip like this by himself.
Penny: He's a grown man.
Leonard: No, he looks like a grown man. You've seen Freaky Friday, sometimes little kids end up in big person bodies.

Leonard: I'm your son. What about the fact that she's good enough for me?
Beverly Hofstadter: *blank shrug* Sure.

Stuart: I don't mean to be rude, Sheldon, but my life is kinda falling apart right now.

Bernadette: I don't think the service is going to send any more people.
Howard: Yeah, maybe it's time we just release Ma back into the sea.

Sheldon: [President Siebert said] that everybody has to do things they don't want to do. He then gave an example of something he had to do although he didn't want to. And that was look at my stupid face.
Leonard: That's a rude thing to say ... out loud.

Sheldon: It's an outrage. Honestly, I am tempted to leave the university.
Howard: You know, if you're really serious about that I hear there are some exciting opportunities in home care for the old and fat.

Beverly Hofstadter: Hello, Leonard.
Leonard: Hi, mom. I have some exciting news.
Beverly Hofstadter: I'm listening.
Leonard: Before I tell you, will you promise to try and be happy for me and keep any concerns you have to yourself?
Beverly Hofstadter: No.

Amy: You hate the sound of all those keys on his keychain.
Sheldon: Four keys! Who does he think he is? A warden?