Leonard: Hey, you want to talk about not getting love from a parent. You know what I used to do when I was little to have some sensation of human contact?
Penny: Yeah, you grabbed your penis and wouldn't let go. Your mother told me.
Leonard: Of course she did. Anyway, that's not what I was gonna say. When I was ten years old, I built a hugging machine.
Penny: A hugging machine?
Leonard: Yeah. I got a dressmaker's mannequin, I stuffed it with an electric blanket so it would be warm, and built two radio-controlled arms that would hug me and pat my back.
Penny: Oh, that is so sad.
Leonard: You know what the saddest part was?
Penny: What?
Leonard: My father used to borrow it.

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Leonard: My point is, while you're spending all this time on your own, building computers or practicing your cello, what you're really doing is becoming interesting. When people finally do notice you, they're gonna find someone a lot cooler than they thought. And for those of you that were popular in high school, it's over, sorry. Thank you. Congratulations.

Beverly Hofstadter: It might explain why the two of you have created an ersatz homosexual marriage to satisfy your need for intimacy.
Howard: Say what?

Leonard: She's only been here a day and a half, and I'm seriously considering alcoholism as a new career path.
Penny: Hey, I talked to her for five minutes yesterday, and I've been half bombed ever since.

Beverly Hofstadter: If you want to have intercourse with that girl, find out what kind of cologne her father wore.