A childhood belief about general

One of my favorite games growing up, however dorky this may sound, was this game where we would put these stickers on the body to match the place they really went. (Actually, this game helped me later on in Biology class, even though i did fail.) All the different part were different colors so i just assumed that inside our body, these were the colors. I also assumed, becuase the game and the stickers were flat, our body parts were also two-dimensional. Soon after, i realiezed they weren't flat, but it took me a long time to figure out that they werent those colors. Even now i wonder...