My kids never performed when I wanted them to. They could know all the animal sounds, the aphabet song, memory verses and other amazing feats. But, when you pulled out the video camera, called Gramma or had an expectant audience waiting, that's what you did - waited for the performance and tried to enduce those little monsters to perform the greatness you knew they possessed.
My grandchild is no different. Even though she is in the gifted and talented program in her Mommy's home, even though there probably isn't a smarter or cuter litle girl around, she just doesn't want to perform. I think she is just a humble genius.