Has anyone besides me noticed that the shapes of Bert's and Ernie's heads have evolved over time? When they first appeared, both Bert and Ernie had heads shaped exactly like American footballs. Bert's was a vertical football and Ernie's was horizontal. The bottom of Bert's head was concealed inside his turtleneck, but as far as you could see, his head was symmetrical top-to-bottom. I suppose this was meant to symbolize the same-but-different aspects of their personalities. Later, Bert's head changed so it is more flattened at the bottom. It has lost its vertical symmetry. You will only notice the change if you see some very old pictures of them.