In our zeal to pursue the Lean Startup methodology (which is an excellent approach), we tend to focus on techniques (MVP! Customer Development!) rather than the underlying abilities you need to apply them successfully.

I think that there is a formula for iterating your way to success:
Willingness to try + Ability to learn + Listening to feedback = Success

Willingness to try:
The odds are stacked against startups.  If you only do the things that conventional wisdom says make sense, you will fail, because giant companies with orders of magnitude more resources are able to follow conventional wisdom.  You need unconventional wisdom to win, which means you need an unusually high willingness to try new things.

Ability to learn:
There is no handbook that tells you what to do (not even “The Lean Startup”).  This means that you need to learn the lessons for yourself.  Your ability to learn those lessons quickly and well will determine whether or not you succeed.

Listening to feedback:
Regardless of how much you learn by reading, talking with experts, or simple experimentation, you need to listen to the feedback that results.  You’ll probably be wrong at least 90% of the time with the things you try; listening to feedback is the only way you’ll be able to decide what constitutes the 10% that does make sense, and that you should build on.