One of the biggest reasons people don't do startups is because they are scared - they like to sit around and talk about them at the watercooler, or circlejerk on startup blogs, but ultimately, for whatever reason, they don't actually sit down and make a plan - perfect it through careful, honest introspection and analysis, and then do it.
via Ask Me Anything: Entrepreneur edition at reddit.com
Amen.
Also enjoyed the quote: "Founding a tech startup is the most fun you never want to have again. But then a few years later...you do it again because something is wrong with you..."