Leonard: You see, I used to be a jackass, but I stopped myself. I became a good guy. See, that's kind of my superpower. I'm like Captain Good Guy!
(Alice pushes him out, then slams door)
Leonard: It's okay. Did the right thing. *tightens his jacket* You idiot!

Howard: That was weird, right?
Leonard: Was it? I honestly can't tell anymore.

Leonard: Next question. Uh, "how close are you with your family?"
Penny: Pretty close.
Leonard: I'm gonna say not too close, but I'm hoping to get farther.

Leonard: "How are you with pets?" Well, I did take care of Sheldon for 15 years, and he only bit me twice.

Amy: Hey, did you guys know that Sheldon had a best friend growing up named Tam?
Leonard: Was that the imaginary talking koala?
Amy: No. He's a real person who apparently betrayed him.
Leonard: Yeah, so did the koala.

Howard: Wow. I wonder what that guy could've done to make Sheldon not talk to him for 20 years.
Leonard: I wonder if it'd work a second time.

Penny: No, it does matter. Okay? You were right. It was Halloween. I was dressed as a cat, you were a hobbit. It was right there on that couch.
Leonard: Why didn't you just say that?
Penny: Because I always hated that was our first kiss. I was drunk, and I was still with Kurt, and I was using you to make myself feel better. I just wanted our first kiss to mean something. That's why I said it was the one on your birthday.
Leonard: I like that. We'll make that our official first kiss.

Sheldon: I suppose you're wondering why I put you through all this.
Leonard: You mean the last two minutes or the last 20 years?

Sheldon: You know we're almost finished with our paper; we just need help tracking down the citations.
Leonard: That's busywork. Can't you just get a grad student to do it?
Amy: No, this paper is incredibly important to us, and we need someone we can trust.
Please, it would mean a lot.
Leonard: You know what? Sure. The three of us in the library looking up old papers, that actually could be kind of fun.
Sheldon: Oh, no, we won't be there.
Leonard: It just got more fun.

Leonard: What is up with you two?
Stuart: Well, it's kind of hard to explain. Uh, you know when things are going great, but you worry that any minute you might screw everything up?
Penny: No.
Leonard: Yes. If you really like her, you can't let fear get in the way. You have to move forward.
Stuart: And at a certain point, the fear of losing her goes away?
Leonard: I will let you know.

Penny: I mean, come on, when was the last time you did something totally selfish without worrying about what anyone else wanted?
Leonard: Uh, according to my mother, I took my sweet time being born.
Penny: How is that selfish?
Leonard: Apparently, she had dinner reservations.

Amy: Are you really not gonna pick up your mother?
Leonard: No. It's fine, she likes to take a cab or a shuttle. That way she can meet people.
Amy: Well, that's kind of nice.
Leonard: Yeah, she always says that a stranger is just a person whose emotional weak point you haven't found yet.
Sheldon: Your mom is the best.

Penny: Well should we wake him up?
Leonard: Well, he did say if he fell asleep, we were allowed to slap him awake.
Penny: Oh, boy.
Leonard: Wait a minute. Why do you get to do it?
Penny: 'Cause I called it.
Leonard: Well, you can't just call it. You have to earn it.
Penny: Oh, and you've earned it?
Leonard: No one has earned it more than me. [Amy clears her throat] You have your whole life to smack him around. This is my time.

Leonard: Okay, you need to focus on the positive. You won a Nobel Prize. I slapped Sheldon. A lot of dreams came true today.

Leonard: [answering the phone] Hello. Hey. It's Howard. Oh, us, too.
Penny: Wait, what?
Leonard: They're gonna stay. The kids are fine. Bernie's parents took over. Really? Oh, poor little guy.
Penny: Is Michael okay?
Leonard: Yeah, it's Stuart. Bernie's dad gave him a hug, cracked a rib.