You want to achieve a goal with your idea.
I’m not talking about the obvious ones: wealth, freedom, fame. I’m talking about the purpose of your idea, what it tries to do, the problem it tries to solve.
Your idea came to life to do exactly that, but what exactly is that?
Your idea, the things that make it take a problem and create a solution, can and will be different if the context of implementation changes.
If you change the final manifestation of your idea (the product or service), it will fulfill a new goal, solve a different problem, for other people.
Listerine was initially developed as a surgical antiseptic, not as a solution for bad breath. The Listerine you know today, has the same essential mechanism. But it is a new solution to a different problem for another audience.
Ill-defined goals will lead you astray. You can change the manifestation of your idea, even during implementation. Still, if you want it to have a better chance for success, you need to make sure you know what its goal is - what it does explicitly and for who.