If your goal is to make money, becoming an entrepreneur is a sucker's bet. Sure, some entrepreneurs make a lot of money, but if you calculate the amount of stress-inducing work and time it takes and multiply that by the low likelihood of success and eventual payoff, it is not a great way to get rich.

If we do not know who the customer is, we do not know what quality is.

The way forward is to learn to see every startup in any industry as a grand experiment.

Products a start-up builds are really experiments…Learning about how to build a sustainable business is the outcome of those experiments [which follow] a three-step process: Build, measure, learn.” “[A startup is] … an organization dedicated to creating something new under conditions of extreme uncertainty.

Progress in manufacturing is measured by the production of high quality goods. The unit of progress for Lean Startups is validated learning-a rigorous method for demonstrating progress when one is embedded in the soil of extreme uncertainty.

Nowadays people talk about PayPal's founders as prescient geniuses who would inevitably change the world. It was, however, not so obvious that PayPal would taste its first major success by helping people sell Beanie Babies on eBay. But they had a vision, a hope, and the perseverance to try multiple iterations until they got it right.

The hardest part is the grueling work of constantly being wrong.