What you speak is an expression of who you are. Everyone needs a sounding board, a feedback system. Because then you won't, even if you could. Language is the bridge where body meets the soul. Talking aloud keeps you from falling asleep and day- dreaming.
Words are reality.
We all make mistakes. We should always discuss our ideas with another person because we're much more objective about others than we are about ourselves. Close friends do more than just correct mistakes. It stimulates and expands your ideas. If you want greatness, you need people to help you make it.