With that, Mad Men is over. One of the greatest television dramas about the rise and fall of an entrepreneurial venture (and the people who live for it) has gone on to the land of reruns and binge watching.

Of course there was a heck of a lot more going on in this show, but if you watched with the eyes of an entrepreneur, the most interesting parts usually had to do with the business itself. Even as we thought things were going to get all sentimental, in a brilliant last scene, it all came back to business.

Over the years, there were some awfully good pointers about how to be a successful entrepreneur, or, for that matter, simply how to be successful in any professional endeavor. Meanwhile, others have taken the show apart--looking at everything from its parenting lessons to why the women characters were much more interesting than the men.

But before we all switch our fictional business allegiances over to HBO's Silicon Valley, here are the top dozen things we all learned. (Be warned: spoilers follow.)

1. Find what truly matters

At last count, I think there were 13 divorces, 21 estranged relationships, and probably three dozen people who needed to get to an AA meeting ASAP on this show. In the finale, the last crushing conversation Don has with his ex-wife, Betty, involves her telling him that it would be best for his kids to "keep things as normal as possible" by not being around. (Runner up: Stan telling Peggy: "There's more to life than work..." although they wind up together, so it's a lot sweeter.) It's a pretty clear message that those who don't find what truly matters in life don't do very well.

2. Don't become attached to the wrong things

This is the other side of that same point. In fact, finding what truly matters in life--and avoiding what doesn't--is probably the ultimate lesson of this show. The pretty reasonable takeaway is that nobody is satisfied by just one thing. I think these days we call it "work-life balance."

3. Just start

Back to business. You know that saying about how if you don't know what to do, just start doing it? Case in point: Joan in the finale launching a new business from her kitchen table. Build your rocket ship on the way to the moon.

4. Lead your customers

Decades before Steve Jobs and Steve Wozniak launched Apple, the fictional characters of Mad Men understood that business is better when you can predict the future. If you ask customers what they want, they'll want something else by the time you can deliver it. So you have to figure it out before they do.

5. Head toward the action

Whether it's all of the travel to California, or Pete Campbell heading to Learjet in Kansas, staying in one place is rarely the answer. Action begets opportunity.

6. Understand the numbers

I've been harping on this one ever since we saw one of the characters (Pete Campbell, in fact) wildly miscalculate the valuation of Sterling Cooper & Partners and how much money he'd make when it was acquired. If you can't figure out your own spreadsheet, it's hard to stay solvent.

7. Find your passion

Oh wait, maybe this might be the lesson of the entire series. For Joan, it turns out to be business; for Peggy, it turns out to be a love she never noticed. And for Don--well, I did warn there were spoilers, but it turns out to be work. It's truly the only thing he's ever really successful at throughout the entire series, and it's where his mind goes when he finally reaches inner peace above the Pacific Ocean.

8. Let your creative side shine

Don once explained the way his creative process works: Think as hard as you can about your problem, then forget about it and let your subconscious do the work. Lo and behold, it works for him once again in the finale (and brings about one of the most iconic television commercials of the 1970s).

9. Leverage technology

First it was medical research about smoking, then it was television, then it was computers. Figure out how technology will affect your business--and get way ahead of the curve.

10. Take care of your network

There are so many examples of this--from the fact that back in the original days of Sterling Cooper, Don Draper networked his way into a fake job, to the view of Joan being able to launch her new business because she's got a giant Rolodex of people to contract with. But remember: You have to take care of your network if you sometimes want to draw on it.

11. Take care of the people you lead

A couple of episodes short of the end, when Don Draper and Roger Sterling announced that SC&P would be absorbed into McCann Erickson, we saw just how little sway they had over their employees--especially when the employees realized they no longer cared about them. Don't be that kind of leader.

12. Quit when it's time

It's not true that people usually only get one chance in life--but it is true that you don't get unlimited chances. So don't blow them by going after things that aren't worth your time. Part of that means recognizing that when it's time to finish doing one thing and start another--you actually have to stop doing the first thing. And after seven seasons spread out over nearly eight years, it feels like Mad Men finally took its own advice.