I've been reading Eric Carle's "Polar Bear, Polar Bear" every night to my son for the past three weeks. He's really into it. His favorite animal is the peacock. We make the sound together and then he says "Butterfly". Then I say "No. Peacock". Then he says "Peacock" in a dejected way that makes me feel like I should have just let him think that the peacock was a butterfly.