Things that go Bump...

Driving to school the other day, I hear Lily from the backseat. "Mom, what's this mean?" I glance in the rear-view mirror and see her giving a thumbs up sign. Doing my best Fonzie impersonation, I say "Aaaaaaaaayyyy....Thumbs up means good job, okay. Aaaaaaayyyy...." Can you say that? She pauses, ponders her response and finally says, "No, I can't do bumpy sounds."