Apparently one from the old days when things were hand-made by people and child labor was not a crime ...

The floor manager of the local brush factory is impressed by a young girl who has joined recently, worked hard and perfected her job in a short time. However he is shocked when one day she comes to him all distraught and declares that she is quitting with immediate effect. She is reluctant to tell him the reason and it takes him all his tact to make her speak.

After much prodding, she tells him - "I've been making so many of these damn brushes every day, nobody told me about how it would affect my body. Now I have brushes growing all over me!"

The manager can't make sense of this and pleads her to explain further. Again after much persuasion she shows him what is clearly evidence of her puberty.

The manager sighs and gives her the long talk about the whole thing and tells her everyone goes through it, with hair sprouting in all the inconvenient places. When the girl refuses to believe him, he is (perhaps easily) compelled to provide evidence of his own growth.

The girl, instead of being convinced, gets even more hysterical and shrieks "yours is worse, it has even grown a handle!"

(reconstructed from vague memory, couldn't find the source. feel free to re-write for better effect)

no need for a rewrite