This is very sound advice. I think many people are afraid to take that big leap into business because they believe their product must be a genius idea that will be an instant big hit. I would love to know how many successful companies started with a failed product that was later improved. I think the first iteration is rarely the best, so it is essential to plan for some real flops also.
A first failure should not prevent you from moving on to plan B. Sometimes the key is just to put yourself out there, learn the ropes and actually launch the brilliant idea when everything else is in place and you feel ready for it.