There is some evidence that exposure to germs at an early age builds the immune system.
Some kids that live antiseptic childhoods have immune system problems later, like allergies (an overreaction by the immune system).
In 1948-49, our family doctor gave my mother this same advice. I still remember my mother’s astonished reaction.
I was full of high hopes for both diet and hygiene when my daughter was born.
It eroded when I caught her drinking from the dog's water, and finally died the day I caught her drinking from the pond. The pond that the fish poop in; the pond that the frogs have sex in.
Despite this, she lives, and only 15 more years until I can kick her out!