I saw The Social Network last Friday night, and enjoyed it thoroughly. When it was over I was surprised. “What? Two hours already?”

Here are 10 (mental) notes I took as I watched:

1. This movie is fun. Aaron Sorkin (of West Wing and Studio 60) does a great job making entertainment from reality.
2. The plot feels real. I have no first-hand knowledge of Mark or Facebook, but I’ve done angel investing, raised VC money, and was a founding director of a software company that went public. And it feels to me like how these things happen.
3. The Mark character rings true. He’s brilliant, obsessive, extremely productive, abrasive, selfish, and driven. I’ve known some people like that. They get things done. They bump people around on the way, more from blind obsession with their goals than on purpose. They’re not real good at seeing two sides of any question. They build empires.
4. Ideas have little or no value. Implementation is what matters. Facebook grew out of some similar ideas that others had first. Mark took them and made them Facebook, and those others didn’t.  When reminded that others had a similar idea first, the Mark character points out that if it had been left to them, it would never have grown into what Facebook became. I agree. The race goes not to the alleged originator of the idea, but to the person who took that idea and built a business out of it.
5. This movie is not bad for Facebook or for Mark Zuckerberg. We should all be so lucky. What happened with Facebook is a one-of-a-kind business phenomenon and this movie reinforces that. And the Mark character isn’t bad guy or good guy, he’s techie nerd obsessed business founder. It won’t hurt him at all. Mark can cry all the way to the bank. I like Ben Parr’s Mashable post on the real Mark Zuckerberg’s feelings about the movie after it rolled out. And I like this NYTimes.com analysis (you may have to register to see it, but registration’s free) of Facebook’s lack of legal options to do anything but watch.
6. I don’t feel sorry for the three guys who came up with the original idea. The idea was obvious. They didn’t implement it. Mark stalled them with misinformation, which isn’t nice, but then ideas aren’t owned, so they can’t be stolen; just implemented.  (Corollary to note #4)
7. The guy who wrote checks has a better argument. There are at least two sides to his story, and I doubt that the movie tells his side very well.   It doesn’t add up right. I do believe that writing checks into a business early on gives you some real ownership.
8. Always get it in writing. There’s a lesson for entrepreneurs everywhere: sure it’s awkward among friends, but even if it’s not a legal document write it down and sign it. Maybe it’s just a reminder for you and partners later. Maybe you keep it in terms you understand. Ideally, you work with a lawyer to make it legal. It’s very important to do this early, before success or failure, because that keeps motivations cleaner.
9. You have to protect yourself, not trust in friendship, good will, or ethics. Good intentions and verbal promises get lost in the shuffle. Business is like that. Never trust what somebody tells you a legal document says; read it. When somebody else is working with an attorney, get an attorney.
10. The real world is full of great stories. It doesn’t take a space fantasy or super hero to make a great movie plot. Real people, the real world, and even real business can be very entertaining. And hey, if we get a few lessons along the way, everybody wins. Right?

For the record, the notes here were mental notes only. I didn’t get my phone out and type into it during the movie. So movie goers, don’t worry. That wasn’t me.