This is just a cool quote, but think of it. When Walt Disney told MGM studios about the character of Mickey Mouse, they said it was a bad idea that would scare people away. Have you ever been met by someone who said that your idea was bad? Did you listen to them? Can you imagine what would have happened to Mickey Mouse if Disney had listened to the directors of MGM back in 1927? Life on earth would be different. We would, of course, have other animated movies and characters, but it might be that Disney as a company would never had become what it is today.
What is the essence? You should definitely listen to the voice of other people when you have an idea. You should ask for advice and listen to people you look up to and believe understand the market and the world we live in. But in the end, it is entirely up to you to decide what will happen with your idea.
Will you throw Mickey Mouse in the garbage, or will you do like Walt Disney and live the dream, even if people think it is a waste of time and money?