AirBnB happened because Brian Chesky couldn't pay his rent, but did have some space.

Another way of looking at this, is that the best companies are almost always mission oriented.

Cofounder relationships are among the most important in the entire company.

You also really want to take the time to think about how the market is going to evolve.You need a market that's going to be big in 10 years.

Move fast. Speed is one of your main advantages over large companies.

You need someone that behaves like James Bond more than you need someone that is an expert in some particular domain.

If you're not in college and you don't know a cofounder, the next best thing I think is to go work at an interesting company.