However, while it might be thrilling to discover fun facts about the human body, there are also some unsettling truths you might prefer to ignore. If you are diabetic, and don't know it--or do, but have problems controlling your sugars, it can severely harm your teeth. ADVERTISEMENT#9 Not necessarily a medical fact, but a reality check: Doctors don't have everything figured out, they are just human like the rest of us. ADVERTISEMENT#18 That doctors don’t know everything and you can go years without getting a diagnosis while being in unspeakable pain. What most people don't know is what it's made of.