Don't wait for everything to be perfect before you test your idea in the market and before you sell to customers. Be open to feedback. Don't be afraid to change your idea if need be. Also, remember that "the real value" in your idea might not be where you think it is.
I really worry when I see entrepreneurs spend so much time "thinking about doing " rather than "doing" that they miss important opportunities. An idea without execution is a dream, not a business.
Are you spinning your wheels? If you are still pursuing the same idea as you were 2 or 3 years ago, and you haven't approached any customers or changed your thinking at all, and you still haven't gotten your business off the ground, it's time to get started or get stopped and move onto another idea.
Passion, courage, curiosity, confidence, humility, persistence, resilience and the right people are all required and so is the right TIMING.