You have to start by admitting that you don’t actually know what your customers want.

You have to start by admitting that you don’t actually know what your customers want. When you think you know what they want, if you invest really heavily in building the product for a customer based on a hypothesis that’s wrong, you end up investing lots of time, money, and resources in something that generates no results and isn’t actually what somebody wants. So the Lean Startup methodology is all about defining a hypothesis upfront about what a customer wants, finding the fastest and most efficient way to test that hypothesis, and designing an experiment that can validate or invalidate your hypothesis.

— John McBride