sweet potatoes

As long as we can remember, Enoch has always eaten all the skin off his sweet potatoes. He's the only one who has ever done it. Yesterday, I asked him if he liked eating the skin. He emphatically said no. We all laughed. I told him he didn't have to eat it, that we never eat it and peel it off. He looked very surprised. I wonder where he got the idea he had to eat it the skin