Professor Proton: [on TV] Can a clock be powered by an ordinary potato? I hope so, boys and girls, or this is going to be a really boring episode.

Adult Sheldon: That was the first time I held my father's hand. I wouldn't touch my brother's hand until seventeen years later, thanks to the invention of Purell.

Mary: You understand that some people are going to be intimidated by you, because of how smart you are?
Sheldon: Or maybe they'll recognize my intellect and make me their leader.

Pastor: In Matthew nine, verse four, Jesus said, "Why would you entertain evil thoughts in your hearts?"
Sheldon: Do you have evil thoughts?
Mary: Ssh.
Sheldon: I just don't think this part applies to me.
Mary: That's fine. Be quiet and listen.
Sheldon: I'm only nine years old. Most evil doesn't start till puberty.