While I have a lot of criticisms of the MBA program I was in, I was lucky to get a few important lessons that I think are useful:

1 - From my small business professor: Don't think about it, just do it. If you overanalyze your idea, you'll never start your business.

2 - Guest speaker in advertising: The customer always gets what they deserve.

3 - Economics professor: Most of the experts out there just read a couple more articles more than the next guy.

4 - Same economics professor: If you want to be rich, sail and ski. You'll make your best connections. (I don't do either, but I don't disagree with his assessment)

5 - Strategy classes: Focus on what you're good at

6 - Final Strategy Study: Learning how to work with people you want to fire but can't

Of course, everyone gets different stuff out of their program - it seemed like everyone in my cohort wanted to be a product manager at Proctor and Gamble, but that's another story.