There are literally so many things that can go wrong with the human body. I just learned about this thing called Costochondritis. It's an inflammation of the cartilage in the rib cage. It can cause severe chest pain and might last for months. Why are we so weak? Here is what I think, it is a result of how much our population has increased over the last two centuries. We went from a few hundred million human beings to billions of human beings in such a short time. With more people, there are more cases of malfunctioning bodies. There are more cases of genetic variance leading to weird or rare afflictions. This is what evolution looks like. It doesn't care about us, our intelligence, how special we are -- nature is indiscriminate. The "weak" will be filtered out through natural selection and the strongest genes will prevail. This is a pivotal time, we will either rise to the challenge of becoming the (presumed until further notice, but HOPEFULLY) most advanced species in the universe or succumb to our chimp desires of war and conquest and die in a nuclear fire. It is like that one cliche that each generation mimics... "what a time to be alive"..