Simplified analogies suck... there is more and more evidence that (some) virus infections can have a damaging accumulating effect (it depends though and the bi

Simplified analogies suck... there is more and more evidence that (some) virus infections can have a damaging accumulating effect (it depends though and the biggest factor seems to be the individual). By your simplified analogy it would seem logical to expose oneself to any virus as often as someone does not "overexercise" the muscle, which is really not recommended!!! It doesn't make you stronger, it can weaken and permanetly damage you! Some things are lethal, some things are damaging, hyperhygiene especially in childhood is not good, but still hygiene is a profound reason our civilization does better in many regards.. it is a tight balance everyone needs to decide for his own (and to his own conditions). Please don't propagate that our immune system is a muscle we need to train (in that simplified way).