That last statement is not really a true. There are a great many things which do not kill you and leave long term negative impacts. There are many diseases th

That last statement is not really a true. There are a great many things which do not kill you and leave long term negative impacts. There are many diseases that your body can fight off but long lasting damage remains and that damage can even be passed on to offspring. While people are generally resilient it's a bad idea to knowingly get harmful diseases due to the long term impacts. Your example of Chicken pox parties are regarded as a bad idea universally by the medical field, it would be smarter to get the vaccine. Mother's who want their children to get it are miseducated on the subject. While there will always be something new, modern hygiene practices, when followed, greatly hinder the spread of things until proper treatments and vaccines are developed. One of things that I would like to see happen is the use of natural antibacterial and antiviral metals used for commonly touched items. We know that copper containing alloys do this. I'm sure with study there could be other cheaper ones found which would be an easy augment to standard hygiene.