Sheldon: Here. I'm hoping once you reap the endorphic rewards of the steady clickety-clack of steel wheels on polished rails, your sour disposition will abate.
Leonard: Yeah, maybe. Meanwhile back in the 21st century, people are raising their tray tables and putting their seat-backs in an upright position 'cause it's time to land in San Francisco.

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: 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.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Sheldon: She calls me moon-pie because I'm nummy-nummy and she could just eat me up.

Leonard: Well, it looks like you're caught between a rock and a crazy place.
Sheldon: I hate when that happens.

Sheldon: No one calls me Moon Pie but Meemaw.