Here is a fundamental thing I've learnt about startups that is hugely important and massively over looked: You need to be passionate about building a company,

Here is a fundamental thing I've learnt about startups that is hugely important and massively over looked: You need to be passionate about building a company, not an idea. Because you will change the idea, and if your passion isn't in running a company you're dead. The groupon guy doesn't care about group buying, he cares about building a company with x culture etc.