What I'm about to tell you might be slightly disturbing. Right now, there is a skeleton inside of you. And your skeleton is alive. As you're inhaling and exhaling air... so is your skeleton. So is your skin, your knees, your internal organs, your eyeballs, all breathing and alive. Oh so very alive. Inside you. You're just a brain wearing bone armor and a meat suit. Your brain knows so many things, it's just not telling you. Ever done a test and found that you forgot everything even though you studied the night before? That's your brain hiding the answers from you where you will never find them until it's too little too late. What if the air is actually slowly killing us. In fact there could be a number of things that could just be slowly killing us and we'd have no idea and we just think that's the average human life-span. There's actually more we don't know about our own body than stuff we do know. There's a chance that humans will lose their toes in hundreds of years. This is because, nowadays, we no longer need our toes to stand up and balance. Older humans had better teeth because their skulls were bigger, their diets were better and their teeth were stronger. Evolution just ruined us. History doesn't repeat itself. We repeat history.