Stick to Your Knitting

Who thinks of these idioms? I'd be interested in learning the history behind this one.

Stick to knitting: if a person or company sticks to their knitting, they continue to do what they have always done instead of trying to do something they know very little about. He believes the key to a company's success is to stick to its knitting rather than trying to diversify.

From The Free Dictionary

The things you learn each day.