What do people who are nomads do? How 'unhealthy' are they? However is it possible for one of those to live to old age? Everyday risks are overblown unnecessar

What do people who are nomads do? How 'unhealthy' are they? However is it possible for one of those to live to old age? Everyday risks are overblown unnecessarily. What we need today is more of what I was told about as a child: "Good, clean, dirt". How do you build up immunity to everyday germs without some form of exposure? Washing under running water is sufficient for practically all purposes with unbroken skin. As today's nomads and all the generations of non-modern people have done for thousands of years.