The quicker you fail, the quicker you move on to your next success.
If you’re wondering whether you should move on your next idea, do it. Like any decent scientist would, go out and test your hypothesis. Don’t sit around in a state of indecision for long. Make a decision, if you make the wrong decision, then correct your course. It’s much harder to steer a parked car.
Ed Catmull in the book Creativity Inc. puts it this way:
The cost of failure is an investment in the future
I’m not glorifying failure, but to understand that failure is a natural progression of success is crucial to creating forward momentum, and those who don’t fail often don’t succeed. This post I’m writing right now might just be a complete failure, but it doesn’t matter. As soon as I hit publish I’m moving on to my next idea.
The only surefire way to avoid failure is to do nothing.
Related: If you need further encouragement, here's a list of famous people who failed at first, and often miserably.