A summary of Zuckerberg at Startup School 2012.
I really like this quote from 17.34 in the video:
I never really understood the psychology of deciding you want to start a company before you understand what you want to do
Too many want to be in a startup and work on some half-arsed and not-remotely-considered idea instead of letting it distill in their heads, figure out how they are going to make it and then build something around this structure. Some great insights from Zuckerberg and it really seemed they had insane focus even from day one.