Bachelors' wives and maids' children are always well taught.

An imagined household is easy to manage: a person without a spouse or children can be certain that their future family would behave just as they wish.

The proverb mocks the confidence of people who prescribe simple answers to the difficulties of marriage or childrearing without having faced those difficulties themselves.

Use it in response to a confident claim about how easily someone would manage a spouse or raise a child. It challenges the gap between plans made in the abstract and the demands of family life, though its wording can sound condescending.