Ideas are a dime a dozen. There are literally billions of ideas out there. The real question is not whether you have an idea but whether that idea is an opportunity. Is it worth your time, effort, and money to pursue? Is there a real market opportunity worth the sacrifice that entreprenuership requires? Why waste $5,000,000 and five years or $10,000 and one year on an idea that is going to fail anyway? Instead, fail in five months with $5,000 or in one month for $100. Then take what you have learned and change direction or move on to the next idea until you find the opportunity that has real merit - the idea that is worth your time and energy.
When Clayton M. Christensen, Professor at Harvard Business School and best-selling author, was asked what separates successful from unsuccessful new ventures, he answered, "Successful startups are the ones who have enough money left over to try their second idea." This profound answer implies that you will most likely change your first idea. So why not figure out what's wrong (or right) about an idea as quickly and cheaply as possible.
At the heart of it, successful entrepreneurs redefine what failure means. Pursuing a rapid experiment and finding out you were wrong and changing directions isn't failure. You could have wasted years and your personal fortune. Instead, you saved yourself all that time and money, and you are now one step closer to finding the real opportunity. Congratulations!
By remembering to fail fast, you focus on rapidly testing your assumptions, iterating swiftly, and then, because you have less attachment to your idea, you can see when you need to abandon one approach in favor of a better one. After you've "failed," try a new angle, change direction, or pursue a new idea.
(See Nail It Then Scale It, pgs. 40-43)