Sheldon: Oh, I see why you're confused. No, her news sounded important, but what your forgetting is it was an achievement in the field of biology. That's all about yucky, squishy things. Penny: Honey, she's upset. You're her boyfriend. You have to at least try to be excited by the things she's excited by. Sheldon: What if they simply don't excite me? Penny: Well, just smile and think about koalas.