The human heart is one of the biggest miracles the world has ever seen. I have a friend who is fascinated by the way the human heart works. Anyway, you do not need to be a doctor to have some knowledge about the human body. Personally, I used to like biology classes at school. As a matter of fact, they used to be my favorite classes. Learning about nature and everything that is in it was always an interesting experience to me. I liked other classes as well, but this was my favorite one. Learning about the human body can be quite interesting, so why don’t you give it a try one day?