It’s because they don’t understand there’s different types of germs.

Commensal germs are the bacteria/viruses present in your (natural) environment. They’re like giving your immune an opportunity to exercise.

Pathogenic germs are the bacteria/viruses that cause illness in people/animals. They’re like hitting your immune system with a lead pipe.

With my kid we call them “nature germs” and “sick germs.” It’s not that difficult of a concept. They know the difference and they’re 3-years-old.

Sp many people have been conditioned to think “what doesn’t kill you makes you stronger” about health in general. They wrongly believe pathogenic bacteria/viruses are what “strengthen your immune system.” That’s not entirely untrue. Just like it’s not entirely untrue that putting some kind of liquid in my car will make it go.

Another thing that bothers me about people’s misconceptions about their own bodies is how they treat the immune system as separate from the rest of the body. You’re telling me things like my eyes, things I use to see snot dripping out of another persons face, aren’t part of the system that keeps my body healthy?

If you want a strong immune system then drink water, eat nutritious food, get good sleep, and touch grass, and try not to get sick.