Quote from the episode Carbon Dating and a Stuffed Raccoon
Paige: I'm so happy to see you. Are you happy to see me?
Sheldon: Not immediately.
Paige: That's okay. I'm happy enough for both of us.
Quote from the episode A Rival Prodigy and Sir Isaac Neutron
Paige: You actually believe in the multiverse theory?
Sheldon: Very much so. It's the most elegant interpretation of quantum mechanics.
Paige: So you really think there are an infinite number of universes?
Sheldon: Stephen Hawking believes it, so, yes, I do.
Paige: Well, if there are an infinite number of universes, I think that theory's dumb in all of them. [CHUCKLES] This is fun.