The lesson is not, as prosecutors would have us believe, that people should not lie to government investigators when questioned about stock transactions.
The guilty verdict against Stewart struck me as a Leona Helmsley-style conviction on Hillary Clinton-style charges: Whatever the indictment said, Martha Stewart was convicted for being arrogant.
The jurors who spoke to reporters gave several explanations for their vote, but it all sounded like "let's teach the high and mighty lady a lesson" to me.
They didn't like that she didn't testify. They didn't like that she had her fancy friends in court. They didn't like that she gloated about the stock tips she picked up from her fancy friends. They didn't like that she bullied her subordinates.
They didn't like that she didn't bother to put on a defense. And they didn't like that she thought she was above the law.
Future Marthas beware: None of these things is against the law, but they go against the grain of the regular citizens who will be more than happy to put you in your place from their spot in the jury box.
We all thought Martha Stewart was better than us. We even laughed about it and ridiculed ourselves.
We just didn't like the fact that she thought so, too. Her jury contained eight women, and women are notorious for slapping down other women who presume too much.
But I am not sure Martha Stewart could presume too much.
She changed American culture in a way that may never be done again.
Long before 9/11 sent us scurrying to the comfort of the hearth, Martha Stewart made us feel differently about our homes and the things we do there for our families.
She taught us that even small tasks are worth doing well. She gave us pride in home-making.
She taught us to cherish holidays and rituals and traditions and family. She taught us those simple household lessons we failed to learn from our mothers and grandmothers.
American home craft for the last 30 years will forever be known by a single name: Martha.
At the same time, she triggered our not-so-latent insecurities with her obsessive perfection. Many of us responded with resentment, and that resentment was the elephant in the courtroom during her trial.
They are already talking about taking Martha's name off the magazine and off her product line. Maybe even off the company she founded.
They think they can save the franchise by distancing themselves from a convicted felon, but they are kidding themselves.
"Martha Stewart" wasn't just a brand name. It was the personal sense of style generated by the peculiar demons that drove this particular woman.
Those same demons, of overcompensation, of over-control, of perfection, apparently caused her to act to save a lousy $45,000 before her ImClone stock tanked - a paltry sum when compared to her billion-dollar stake in her company.
The money she saved certainly had to mean less to her than the idea of losing.
She compounded that sin with the kind of arrogance that would go uncommented upon if she were a man: She dared the government to prove its charges. She refused to believe the governing principle of federal prosecution applied to her - if they indict you, they have enough to convict you, so plea bargain.
The final lesson to all the Marthas who will vie to take Martha's place (and she has spawned dozens) is this: Holster your glue guns and slink out of town.
There will never be another Martha Stewart.