It's very simple. Scissors cuts paper, paper covers rock, rock crushes lizard, lizard poisons Spock, Spock smashes scissors, scissors decapitates lizard, lizard eats paper, paper disproves Spock, Spock vaporizes rock, and, as it always has, rock crushes scissors
Amy: Sheldon, there's something else I've been wanting to say, but before I do, I just... I want you to know that you don't have to say it back.I know you're not ready, and I don't want you to say it just because social convention dictates... Sheldon: I love you, too. Amy: You said it. Sheldon: There's no denying I have feelings for you that can't be explained in any other way. I briefly considered that I had a brain parasite. But that seems even more far-fetched. The only conclusion was love.