Dave: OMG! Aren't you Leonard Hofstadter?
Dave: I saw you speak at Stanford with Sheldon Cooper! Amy, can you believe it? It's Dr. Leonard Hofstadter!
Amy: No. Pinch me.
Dave: It's an absolute pleasure to meet you. Can I shake your hand?
Leonard: I don't know if you want to do that, I was just-
Okay, never mind.
Dave: Amy, I'm never washing this hand again.
Leonard: You really should.